LTC4151/LTC4151-1High Voltage I2C Currentand Voltage Monitor FEATURES
n n n n n nDESCRIPTION
The LTC®4151 and LTC4151-1 are high side power monitors that operate over a wide voltage range of 7V to 80V. In default operation mode, the onboard 12-bit ADC continuously measures high side current, input voltage and an external voltage. Data is reported through the I2C interface when polled by a host. The monitors can also perform on-demand measurement in a snapshot mode. The LTC4151 features a dedicated shutdown pin to reduce power consumption. The LTC4151-1 features split I2C data pins with data in and an inverted data output to drive optoisolators.L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.Wide Operating Voltage Range: 7V to 80V12-Bit Resolution for Both Current and VoltagesI2C InterfaceAdditional ADC Input Monitors an External VoltageContinuous Scan and Snapshot ModesShutdown Mode (LTC4151) Reduces Quiescent Current to 120μAn Split SDA for Optoisolation (LTC4151-1)n Tiny 10-Lead MSOP and 3mm × 3mm DFN PackagesAPPLICATIONS
Telecom Infrastructuren Automotiven Industrialn ConsumernTYPICAL APPLICATION
1.0
12-Bit ADC DNL and INLHigh Side Power Sensing with Onboard ADC and I2CVIN
7V to 80V
0.02ΩVOUTSENSE+SENSE–2kVINLTC4151SHDNSCLSDAADINGNDMEASUREDVOLTAGE2k3.3VADC DNL (LSB)0.5
0
VDDμCONTROLLERSCLSDA41511 TA01–0.5
–1.0
010242048CODE
30724096
41511 TA01b
ADR1ADR01.0
0.5ADC INL (LSB)0
–0.5
–1.0
010242048CODE
30724096
41511 TA01c
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LTC4151/LTC4151-1ABSOLUTE MAXIMUM RATINGS
(Notes 1, 3)VIN Voltage .................................................–0.3V to 90VSENSE+, SENSE– Voltages ..........................VIN – 10V or –0.3V to VIN + 0.3VADR1, ADR0 Voltages .............................. –0.3V to 90VADIN, SHDN, SDAO Voltages ...................... –0.3V to 6VSCL, SDA, SDAI Voltages (Note 2) ........... –0.3V to 5.5VSCL, SDA, SDAI Clamp Current .............................. 5mAOperating Temperature Range LTC4151C/LTC4151C-1 ............................0°C to 70°C LTC4151I/LTC4151I-1 ..........................–40°C to 85°CStorage Temperature Range MSOP ................................................–65°C to 150°C DFN ....................................................–65°C to 125°CLead Temperature (Soldering, 10 sec) MSOP Only .......................................................300°CPIN CONFIGURATION
LTC4151TOP VIEW
SENSE+
VINADR1ADR0ADIN
12345
11
10SENSE–9GND8SHDN7SDA6SCL
TOP VIEW
SENSE
VINADR1ADR0ADIN
+
LT415112345109876
SENSE–GNDSHDNSDASCL
DD PACKAGE
10-LEAD (3mm s 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 45°C/WEXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONALLTC4151-1TOP VIEW
SENSE+
VINADR1ADR0ADIN
12345
11
10SENSE–9GND8SDAO7SDAI6SCL
LTC4151-1MS PACKAGE
10-LEAD PLASTIC MSOPTJMAX = 125°C, θJA = 85°C/WTOP VIEW
SENSE
VINADR1ADR0ADIN
+
12345109876
SENSE–GNDSDAOSDAISCL
DD PACKAGE
10-LEAD (3mm s 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 45°C/WEXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONALMS PACKAGE
10-LEAD PLASTIC MSOPTJMAX = 125°C, θJA = 85°C/W41511fa2元器件交易网www.cecb2b.com
LTC4151/LTC4151-1ORDER INFORMATION
LEAD FREE FINISHLTC4151CDD#PBFLTC4151IDD#PBFLTC4151CDD-1#PBFLTC4151IDD-1#PBFLTC4151CMS#PBFLTC4151IMS#PBFLTC4151CMS-1#PBFLTC4151IMS-1#PBFTAPE AND REELLTC4151CDD#TRPBFLTC4151IDD#TRPBFLTC4151CDD-1#TRPBFLTC4151IDD-1#TRPBFLTC4151CMS#TRPBFLTC4151IMS#TRPBFLTC4151CMS-1#TRPBFLTC4151IMS-1#TRPBFPART MARKING*LCWZLCWZLCXCLCXCLTCWYLTCWYLTCXBLTCXBPACKAGE DESCRIPTION10-Lead (3mm x 3mm) Plastic DFN10-Lead (3mm x 3mm) Plastic DFN10-Lead (3mm x 3mm) Plastic DFN10-Lead (3mm x 3mm) Plastic DFN10-Lead Plastic MSOP10-Lead Plastic MSOP10-Lead Plastic MSOP10-Lead Plastic MSOPTEMPERATURE RANGE0°C to 70°C–40°C to 85°C0°C to 70°C–40°C to 85°C0°C to 70°C–40°C to 85°C0°C to 70°C–40°C to 85°CConsult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.Consult LTC Marketing for information on non-standard lead based fi nish parts.For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/ELECTRICAL CHARACTERISTICS The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN is from 7V to 80V, unless noted. (Note 3)SYMBOLGeneral VINIINISENSE+ISENSE–VSHDN(TH) ISHDNADCRESVFSResolution (No Missing Codes)Full-Scale Voltage(Note 4)(SENSE+ – SENSE–)VIN ADIN(SENSE+ – SENSE–)VIN ADIN(SENSE+ – SENSE–)VIN (Note 5)ADIN, LTC4151C, LTC4151C-1ADIN, LTC4151I, LTC4151I-1(SENSE+ – SENSE–)VIN (Note 6)ADIN(SENSE+ – SENSE–)VIN (Note 5)ADINlllllllllll PARAMETERSupply VoltageSupply CurrentSENSE+ Input CurrentSENSE– Input CurrentSHDN Input ThresholdSHDN Input CurrentCONDITIONSlMIN7TYPMAX80UNITSVmAμAμAμAVμABitsVIN = 48V, Normal Operation ModeVIN = 12V, Shutdown ModeVIN, SENSE+, SENSE– = 48VVIN, SENSE+, SENSE– = 48VSHDN = 0Vllllll1.212050.11–31281.92102.42.04820250.51.5–51.7300912–8mVVVμVmVmV±1.25±1±0.75±1±5±6±8%%%%LSBLSBLSBLSBLSBLSBLSBLSB Step SizeTUETotal Unadjusted ErrorVOSOffset ErrorINLIntegral Nonlinearity±1±1±0.5±3±3±241511fa3元器件交易网www.cecb2b.com
LTC4151/LTC4151-1ELECTRICAL CHARACTERISTICS The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN is from 7V to 80V, unless noted. (Note 3)PARAMETERTransition NoiseCONDITIONS(SENSE+ – SENSE–)VINADINlSYMBOLMINTYP1.20.322MAXUNITSμVRMSmVRMSμVRMSσTfCONVtCONVRADINIADINI2C InterfaceVADR(H)VADR(L)IADR(IN)VSDA(OL)VSDA,SCL(TH) VSDA,SCL(CL) fSCL(MAX)tLOWtHIGHtBUF(MIN)tHD,STA(MIN)tSU,STA(MIN)tSU,STO(MIN)tHD,DATI(MIN)tHD,DATO(MIN)tSU,DAT(MIN)tSP(MAX) tRSTCXConversion Rate (Continuous Mode)Conversion Time (Snapshot Mode)ADIN Pin Input ResistanceADIN Pin Input CurrentADR0, ADR1 Input High ThresholdADRO, ADRI Input Low ThresholdADRO, ADRI Input CurrentSDA, SDAO Output Low VoltageSDA, SDAI, SCL Input ThresholdSDA, SDAI, SCL Clamp VoltageMaximum SCL Clock FrequencyMinimum SCL Low Period Minimum SCL High PeriodMinimum Bus Free Time Between Stop/Start ConditionMinimum Hold Time After (Repeated) Start ConditionMinimum Repeated Start Condition Set-Up TimeMinimum Stop Condition Set-Up TimeMinimum Data Hold Time InputMinimum Data Hold Time OutputMinimum Data Set-Up Time InputMaximum Suppressed Spike Pulse WidthStuck-Bus Reset TimeSCL, SDA Input CapacitanceSCL or SDA/SDAI Held LowISDA, ISDAI, ISCL = 3mAADR0, ADR1 = 0V or 3VADR0, ADR1 = 0.8V or 2.2VISDA, ISDAO = 8mASDA, SDAI, SDAO, SCL = 5V(SENSE+ – SENSE–)ADIN, VINADIN = 3VADIN = 3V6532627.567331098542HzmsmsMΩμAVVμAμAVμAVVkHzllll ±22.30.3±80.1501.65.54000.65500.121403030–100300502060030110335101.36001.360060060009001002501.86.12.650.62.90.9±700.4±226.6llllllllSDAI, SDAO, SCL Input CurrentISDA,SCL(IN) SDA, I2C Interface Timing (Note 4)μsnsμsnsnsnsnsnsnsnsmspFNote 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime.Note 2: Internal clamps limit the SCL, SDA (LTC4151) and SDAI (LTC4151-1) pins to a minimum of 5.5V. Driving these pins to voltages beyond the clamp may damage the part. The pins can be safely tied to higher voltages through a resistor that limits the current below 5mA.Note 3: All currents into pins are positive. All voltages are referenced to GND, unless otherwise noted.Note 4: Guaranteed by design and not subject to test.Note 5: Integral nonlinearity and total unadjusted error of VIN are tested between 7V and 80V.Note 6: Offset error of VIN is defi ned by extrapolating the straight line measured between 7V and 80V.41511fa4元器件交易网www.cecb2b.com
LTC4151/LTC4151-1TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs Supply Voltage (Normal Mode)1.30
400
VIN = 12V, TA = 25°C, unless noted.Supply Current vs Supply Voltage (Shutdown Mode)SUPPLY CURRENT (mA)SUPPLY CURRENT (μA)1.15
–40°C25°C300
–40°C200
25°C85°C100
1.00
85°C0.85
0.70
0
406020
SUPPLY VOLTAGE (V)
80
41511 G01
0
0
406020
SUPPLY VOLTAGE (V)
80
41511 G02
ADC Total Unadjusted Error vs Code (ADIN Voltage)0.10ADC TOTAL UNADJUSTED ERROR (%)1.0
ADC DNL vs Code (ADIN Voltage)1.0
ADC INL vs Code (ADIN Voltage)0.05
ADC DNL (LSB)0.5
ADC INL (LSB)0.5
000
–0.05–0.5–0.5
–0.10
010242048CODE
30724096
41511 G03
–1.0
010242048CODE
30724096
41511 G04
–1.0
010242048CODE
30724096
41511 G05
ADC Total Unadjusted Error vs Code (SENSE Voltage)1.0ADC TOTAL UNADJUSTED ERROR (%)2
ADC DNL vs Code (SENSE Voltage)2
ADC INL vs Code (SENSE Voltage)0.5
ADC DNL (LSB)1
ADC INL (LSB)2048CODE
41511 G06
41511 G07
1
0
00
–0.5
–1–1
–1.0
010242048CODE
30724096
–2
0102430724096
–2
010242048CODE
30724096
41511 G08
41511fa5元器件交易网www.cecb2b.com
LTC4151/LTC4151-1TYPICAL PERFORMANCE CHARACTERISTICS
0.5
VIN = 12V, TA = 25°C, unless noted.SDA, SDAO Output Low vs Pull-Up Current (VSDA(OL) vs ISDA)85°CSDA, SDAI, SCL Clamp Voltagevs Load Current6.3
0.4
25°C0.3
–40°CVSDA,SCL(CL) (V)VSDA(OL) (V)6.2
6.1
–40°C6.0
25°C85°C5.90.01
0.2
0.1
0
0510ISDA (mA)
1520
41511 G09
0.1
ILOAD (mA)
110
41511 G10
PIN FUNCTIONS(DD/MS)SENSE+ (Pin 1): Kelvin Sense of the VIN Pin. See Figure 10 for recommended Kelvin connection.VIN (Pin 2): Supply Voltage Input. Accepts 7V to 80V. The voltage at this pin is monitored by the onboard ADC with a full-scale input range of 102.4V. SENSE+ must be connected to VIN for proper ADC readout.ADR1, ADR0 (Pin 3, Pin 4): I2C Device Address Inputs. Connecting ADR1 and ADR0 to VIN, GND or leaving the pins open confi gures one of nine possible addresses. See Table 1 in the Applications Information section for details.ADIN (Pin 5): ADC Input. The onboard ADC measures volt-age range between 0V and 2.048V. Tie to GND if unused.SCL (Pin 6): I2C Bus Clock Input. Data is shifted in and out at the SDA pin on rising edges of SCL. This pin is driven by an open collector output from a master controller. An external pull-up resistor or current source is required and can be placed between SCL and VIN. The voltage at SCL is internally clamped to 6V (5.5V minimum).SDA (Pin 7, LTC4151 Only): I2C Bus Data Input/Output. Used for shifting in address, command or data bits and sending out data. An external pull-up resistor or current source is required and can be placed between SDA and VIN. The voltage at SDA is internally clamped to 6V (5.5V minimum).SDAI (Pin 7, LTC4151-1 Only): I2C Bus Data Input. Used for shifting in address, command or data bits. This pin is driven by an open collector output from a master controller. An external pull-up resistor or current source is required and can be placed between SDAI and VIN. The voltage at SDAI is internally clamped to 6V (5.5V minimum).SDAO (Pin 8, LTC4151-1 Only): Inverted Serial Bus Data Output. Open-drain output used for sending data back to the master controller or acknowledging a write operation. Data is inverted for convenience of optoisolation. An external pull-up resistor or current source is required.SHDN (Pin 8, LTC4151 Only): Shutdown Input. Internally pulled up to 6.3V. Pull this pin below 1V to force the LTC4151 into shutdown mode. Leave this pin open if unused.GND (Pin 9): Device Ground. SENSE– (Pin 10): High Side Current Sense Input. Connect an external sense resistor between SENSE+ and SENSE–. The differential voltage between SENSE+ and SENSE– is monitored by the onboard ADC with a full-scale sense voltage of 81.92mV.Exposed Pad (Pin 11, DD Package Only): Exposed pad may be left open or connected to device ground (GND).41511fa6元器件交易网www.cecb2b.com
LTC4151/LTC4151-1BLOCK DIAGRAM
VIN
RS2VININTERNALPOWER1SENSE+10SENSE–6.3V5μA25X8SHDN(LTC4151)3ADR14ADR0DECODERSHUTDOWNCONTROLVREF = 2.048V8SDAO(LTC4151-1)735kMUX12-BIT ADCI2C/REGISTERS6V7SDA/SDAI(LTC4151/LTC4151-1)66VSCL15k9GND+5ADIN–41511 BDOPERATION
The LTC4151/LTC4151-1 accurately monitor high side cur-rent and voltages. These devices accept a wide range of input voltages from as low as 7V up to 80V and consume less than 1.7mA quiescent current in normal operation. A shutdown mode is available with the LTC4151 to reduce the quiescent current to less than 300μA by pulling the SHDN pin below 1V. In default continuous scan mode after power-up, the onboard 12-bit analog-to-digital converter (ADC) continu-ously and sequentially measures the high side differen-tial voltage between SENSE+ (Kelvin sense of VIN) and SENSE– (full-scale 81.92mV) through an internal sense amplifi er, the input voltage VIN (full-scale 102.4V) through an internal voltage divider, and the voltage applied to the ADIN pin (full-scale 2.048V). The reference voltage of the ADC is internally set to 2.048V. The digital data obtained by the ADC is stored in the onboard registers. In snapshot mode, the LTC4151/LTC4151-1 can perform on-demand measurement of a selected voltage without the need of continuous polling by a master controller. The snapshot mode is enabled by programming the control register through the I2C interface. A status bit in the data register monitors the ADC’s conversion. When the conver-sion is completed, the 12-bit digital code of the measured voltage is held in the corresponding data registers.The LTC4151/LTC4151-1 provide an I2C interface to read the ADC data from the data registers and to program the control register. Two three-state pins, ADR0 and ADR1, are used to decode nine device addresses (see Table 1). The LTC4151 features a single SDA pin to handle both input data and output data, while the LTC4151-1 provides separate SDAI (input) and SDAO (inverted output) pins to facilitate optoisolation. 41511fa7元器件交易网www.cecb2b.com
LTC4151/LTC4151-1APPLICATIONS INFORMATION
The LTC4151/LTC4151-1 offer a compact complete solu-tion for high side power monitoring. With a wide operating voltage range from 7V to 80V, these devices are ideal for a variety of applications including consumer, automotive, industrial and telecom infrastructure. The simple applica-tion circuit as shown in Figure 1 provides monitoring of high side current with a 0.02Ω resistor (4.096A in full-scale), input voltage (102.4V in full-scale) and an external voltage (2.048V in full-scale), all with an internal 12-bit resolution ADC.Data ConverterThe LTC4151/LTC4151-1 feature an onboard, 12-bit analog-to-digital converter (ADC) that continuously monitors three voltages in the sequence of (VSENSE+ – VSENSE–) fi rst, VIN second and VADIN third. The differential voltage between SENSE+ and SENSE– is monitored with an 81.92mV full-scale and 20μV resolution that allows accurate measure-ment of the high side input current. SENSE+ is a Kelvin sense pin for the VIN pin and must be connected to VIN (see Figure 10) for proper ADC readout. The supply volt-age at VIN is directly measured with a 102.4V full-scale and 25mV resolution. The voltage at the uncommitted ADIN pin is measured with a 2.048V full-scale and 0.5mV resolution that allows monitoring of any external voltage. The 12-bit digital code of each measured voltage is stored in two adjacent registers out of the six total data registers A through F, with the eight MSBs in the fi rst register and the four LSBs in the second (Table 2).The data in registers A through F is refreshed at a frequency of 7.5Hz in continuous scan mode. Setting control register bit G4 (Table 6) invokes a test mode that halts updating of these registers so that they can be written to and read from for software testing.The data converter features a snapshot mode allowing us-ers to make one-time measurements of a selected voltage (either the SENSE voltage, VIN voltage, or ADIN voltage). To enable snapshot mode, set control register bit G7 and write the two-bit code of the desired ADC channel to G6 and G5 (Table 6) using a Write Byte command. When the Write Byte command is completed, the ADC measures the selected voltage and a Busy Bit in the LSB data register is set to indicate that the data is not ready. After complet-ing the conversion, the ADC is halted and the Busy Bit is reset to indicate that the data is ready. To make another measurement of the same voltage or to measure another voltage, fi rst disable the snapshot mode for the previous measurement by clearing control bit G7, then re-enable the snapshot mode and write the code of the desired voltage according to the procedure described above.VIN
7V TO 80V
0.02Ω1SENSE2VINLTC415134+10SENSE–VOUT3.3V2kSHDNSCLSDAADINGND986752kVDDμ-ControllerSCLSDAADR1ADR0VADIN41511 F01Figure 1. Monitoring High Side Current and Voltages Using the LTC415141511fa8元器件交易网www.cecb2b.com
LTC4151/LTC4151-1APPLICATIONS INFORMATION
I2C InterfaceThe LTC4151/LTC4151-1 feature an I2C-compatible in-terface to provide access to six ADC data registers and a control register for monitoring the measured voltages. Figure 2 shows a general data transfer format using the I2C. The LTC4151 and LTC4151-1 are read-write slave devices and support SMBus Read Byte, Write Byte, Read Word and Write Word commands. The devices also sup-port Read Page and Write Page commands that allow one to read or write more than two bytes of data. When using the Read Page and Write Page commands, the host need only to issue an initial register address and the internal register address pointer automatically increments by 1 after each byte of data is read or written. After the register address reaches 06h, it will be reset to 00h and continue the increment. Upon a Stop condition, the register address is reset to 00h. If desired, the Read Page and Write Page support can be disabled by clearing control register bit G3. The data formats for the above commands are shown in Figures 3 to 8. SDAa6 - a0b7 - b0b7 - b0
SCL
S
1 - 7891 - 7891 - 789
P
STARTCONDITION
ADDRESSR/WACKDATAACKDATAACK
STOPCONDITION
41511 F02
Figure 2. General Data Transfer over I2CSADDRESSWA1 1 0 a3:a000COMMANDX X X X X b2:b0ADATAAP0b7:b0041511 F03
SADDRESSWA1 1 0 a3:a000COMMANDX X X X X b2:b0ADATAADATAAP0b7:b00b7:b0041511 F04FROM MASTER TO SLAVEFROM SLAVE TO MASTER
A: ACKNOWLEDGE (LOW)
A: NOT ACKNOWLEDGE (HIGH)R: READ BIT (HIGH)W: WRITE BIT (LOW)S: START CONDITIONP: STOP CONDITION
Figure 4. LTC4151 Serial Bus SDA Write Word ProtocolFigure 3. LTC4151 Serial Bus SDA Write Byte ProtocolSADDRESSWA1 1 0 a3:a000COMMANDX X X X X b2:b0ADATAADATAA......DATAAP41511 F05SADDRESSWA1 1 0 a3:a000COMMANDX X X X X b2:b0AS0ADDRESSRADATAAP41511 F060b7:b00b7:b00b7:b001 1 0 a3:a010b7:b01Figure 5. LTC4151 Serial Bus SDA Write Page ProtocolFigure 6. LTC4151 Serial Bus SDA Read Byte ProtocolSADDRESSWA1 1 0 a3:a000COMMANDX X X X X b2:b0AS0ADDRESSRADATAADATAAP41511 F071 1 0 a3:a010b7:b00b7:b01Figure 7. LTC4151 Serial Bus SDA Read Word ProtocolSADDRESSWA1 1 0 a3:a000COMMANDX X X X X b2:b0AS0ADDRESSRADATAADATA......DATAAPb7:b0141511 F081 1 0 a3:a010b7:b00b7:b0Figure 8. LTC4151 Serial Bus SDA Read Page Protocol41511fa9元器件交易网www.cecb2b.com
LTC4151/LTC4151-1APPLICATIONS INFORMATION
Using Optoisolators with LTC4151-1The LTC4151-1 splits the SDA line into SDAI (input) and SDAO (inverted output) for convenience of opto-coupling with a host controller that sits at a differ-ent ground level. When using optoisolators with the LTC4151-1, connect the SDAI to the output of the incoming optocoupler and connect the SDAO to the anode of the outgoing optocoupler (see Figure 9). With the outgoing optocoupler clamping SDAO and internal 6V (5.5V minimum) clamps on SDAI and SCL, the pull-up resistors on these three pins can be directly connected to VIN. In this way (with SDAO rather than conventional SDAO), the need for a separate low voltage supply for pull-ups is eliminated.Start and Stop ConditionsWhen the I2C bus is idle, both SCL and SDA must remain in the high state. A bus master signals the beginning of a transmission with a Start condition by transitioning SDA from high to low while SCL stays high. When the master has fi nished communicating with the slave, it issues a Stop condition by transitioning SDA from low to high while SCL stays high. The bus is then free for another transmission.VIN48V
1SENSE+2VINLTC4151-134ADR1ADR0GND9SDAISDA0ADIN7855VADINMOCD207M4RS0.02Ω10SENSE–SCL6R120kR220kR35.1k8R40.51k1R50.51kR610kR710kStuck-Bus ResetThe LTC4151/LTC4151-1 I2C interface features a stuck-bus reset timer. The low conditions of the SCL and the SDA/SDAI pins are OR’ed to start the timer. The timer is reset when both SCL and SDA/SDAI are pulled high. If the SCL pin or the SDA/SDAI pin is held low for over 33ms, the stuck-bus timer will expire and the internal I2C state machine will be reset to allow normal communication after the stuck-bus condition is cleared. The stuck-bus timer can be disabled by clearing control register bit G2.I2C Device Addressing Nine distinct I2C bus addresses are confi gurable us-ing the three-state pins ADR0 and ADR1, as shown in Table 1. Address bits a6, a5 and a4 are confi gured to (110) and the least signifi cant bit is the R/W bit. In addi-tion, the LTC4151 and LTC4151-1 will respond to a mass write address (1100 110)b for writing to all LTC4151s and LTC4151-1s, regardless of their individual address settings.3.3VMOCD207M7623SCLVDDμ-Controller18SDA41511 F09237645Figure 9. Optoisolation of the I2C Interface Between LTC4151-1 and a Microcontroller41511fa10元器件交易网www.cecb2b.com
LTC4151/LTC4151-1APPLICATIONS INFORMATION
AcknowledgeThe acknowledge signal is used for handshaking between the transmitter and the receiver to indicate that the last byte of data was received. The transmitter always releases the SDA line during the acknowledge clock pulse. The LTC4151/LTC4151-1 pull the SDA line low on the 9th clock cycle to acknowledge receipt of the data. If the slave fails to acknowledge by leaving SDA high, then the master can abort the transmission by generating a Stop condition. When the master is receiving data from the slave, the master must pull down the SDA line during the clock pulse to indicate receipt of a data byte, and that another byte is to be read. After the last byte has been received the master will leave the SDA line high (not acknowledge) and issue a Stop condition to terminate the transmission. Write Protocol The master begins a write operation with a Start condi-tion followed by the seven bit slave address and the R/W bit set to zero. After the addressed LTC4151/LTC4151-1 acknowledge the address byte, the master then sends a command byte which indicates which internal register the master wishes to write. The LTC4151/LTC4151-1 acknowledge this and then latches the lower three bits of the command byte into its internal register address pointer. The master then delivers the data byte and the LTC4151 or LTC4151-1 acknowledges once more and latches the data Table 1. LTC4151/LTC4151-1 Device Addressing*DESCRIPTIONHEX DEVICEADDRESSa40000000000BINARY DEVICE ADDRESSa30011111111a21100001111a11100110011a00101010101R/W0XXXXXXXXXLTC4151/LTC4151-1ADDRESS PINSADR1XHNCHNCNCLHLLADR0XLHHNCLHNCNCLinto its internal register. If the master continues sending a second byte or more data bytes, as in a Write Word or Write Page command, the second byte or more data bytes will be acknowledged by the LTC4151/LTC4151-1, the internal register address pointer will increment automatically, and each byte of data will be latched into an internal register corresponding to the address pointer. The write operation terminates and the register address pointer resets to 00h when the master sends a Stop condition. Read ProtocolThe master begins a read operation with a Start condition followed by the seven bit slave address and the R/W bit set to zero. After the addressed LTC4151/LTC4151-1 acknowledge the address byte, the master then sends a command byte that indicates which internal register the master wishes to read. The LTC4151/LTC4151-1 acknowledge this and then latches the lower three bits of the command byte into its internal register address pointer. The master then sends a repeated Start condition followed by the same seven bit address with the R/W bit now set to one. The LTC4151/LTC4151-1 acknowledge and send the contents of the requested register. The transmission terminates when the master sends a Stop condition. If the master acknowledges the transmitted data byte, as in a Read Word command, the LTC4151/LTC4151-1 will send the contents of the next register. If the master acknowledges the second data byte ha6a5Mass WriteCC110CE111D0112D2113D4114D6115D8116DA117DC118DE11*H = Tie High; L = Tie to GND; NC = Open; X = Don’t Care41511fa11元器件交易网www.cecb2b.com
LTC4151/LTC4151-1APPLICATIONS INFORMATION
Table 2. LTC4151/LTC4151-1 Register Address and ContentsREGISTER ADDRESS*00h01h02h03h04h05h06h07hREGISTER NAMESENSE (A)SENSE (B)VIN (C)VIN (D)ADIN (E)ADIN (F)CONTROL (G)ReservedREAD/WRITER/W**R/W**R/W**R/W**R/W**R/W**R/WDESCRIPTIONADC Current Sense Voltage Data (8 MSBs)ADC Current Sense Voltage Data (4 LSBs)ADC VIN Voltage Data (8 MSBs)ADC VIN Voltage Data (4 LSBs)ADC ADIN Voltage Data (8 MSBs)ADC ADIN Voltage Data (4 LSBs)Controls ADC Operation Mode and Test Mode *Register address MSBs b7-b3 are ignored. **Writable if bit G4 is set.Table 3. SENSE Registers A (00h) and B (O1h)—Read/WriteBITA7:0, B7:4B3B2:0NAMESENSE Voltage DataADC Busy in Snapshot ModeReservedOPERATION12-Bit Data of Current Sense Voltage with 20μV LSB and 81.92mV Full-Scale1 = SENSE Being Converted; 0 = SENSE Conversion Completed. Not WritableAlways Returns 0. Not WritableTable 4. VIN Registers C (02h) and D (O3h)—Read/WriteBITC7:0, D7:4D3D2:0NAMEVIN Voltage DataADC Busy in Snapshot ModeReservedOPERATION12-Bit Data of VIN Voltage with 25mV LSB and 102.4V Full-Scale1 = VIN Being Converted; 0 = VIN Conversion Completed. Not WritableAlways Returns 0, Not WritableTable 5. ADIN Registers E (04h) and F (O5h)—Read/WriteBITE7:0, F7:4F3F2:0NAMEADIN Voltage DataADC Busy in Snapshot ModeReservedOPERATION12-Bit Data of Current Sense Voltage with 500μV LSB and 2.048V Full-Scale1 = ADIN Being Converted; 0 = ADIN Conversion Completed. Not WritableAlways Returns 0, Not WritableTable 6. CONTROL Register G (06h)—Read/WriteBITG7NAMEADC Snapshot Mode EnableADC Channel Label for Snapshot ModeADC Channel Label for Snapshot ModeTest Mode EnablePage Read/Write EnableStuck-Bus Timer EnableReservedOPERATIONEnables ADC Snapshot Mode; 1 = Snapshot Mode Enabled. Only the channel selected by G6 and G5 is measured by the ADC. After the conversion, the channel busy bit is reset and the ADC is halted.0 = Snapshot Mode Disabled (ADC free running, Default).ADC Channel Label for Snapshot ModeG6001G5010ADC CHANNELSENSE (Default)VINADING6G5G4G3G2G1:0Test Mode Halts ADC Operation and Enables Writes to ADC Registers; 1 = Enable Test Mode, 0 = Disable Test Mode (Default)Enables Page Read/Write; 1 = Enable I2C Page Read/Write (Default), 0 = Disable I2C Page Read/WriteEnables I2C Stuck-Bus Reset Timer; 1 = Enable Stuck-Bus Timer (Default), 0 = Disable Stuck-Bus TimerAlways Returns 0, Not Writable41511fa12元器件交易网www.cecb2b.com
LTC4151/LTC4151-1APPLICATIONS INFORMATION
and each of the following (if more) data bytes, as in a Read Page command, the LTC4151/LTC4151-1 will keep sending out each data byte in the register that corresponds to the incrementing register pointer. The read operation terminates and the register address pointer resets to 00h when the master sends a Stop condition.Layout ConsiderationsA Kelvin connection between the sense resistor RS and the LTC4151/LTC4151-1 is recommended to achieve ac-curate current sensing (Figure 10). The minimum trace width for 1oz copper foil is 0.02\" per amp to make sure the trace stays at a reasonable temperature. Using 0.03\" per amp or wider is recommended. Note that 1oz copper exhibits a sheet resistance of about 530μΩ per square.VINRSILOADSENSE+VINADR1ADR0LTC4151SENSE–GNDGNDILOAD41511 F10Figure 10. Recommended Layout for Kelvin ConnectionTYPICAL APPLICATION
Temperature Monitoring with an NTC Thermistor While Measuring Load Current and LTC4151 Supply Current0.2ΩVIN48V
VISHAY2381 615 4.104100k AT 25°C1%SENSE+SENSE–VINSCLI2C250mALOAD40.2k1%LTC4151ADIN1.5k1%SDAADR1GNDADR041511 TA02T(°C) = 58.82 × (NADIN/NVIN – 0.1066), 20°C < T < 60°C.NADIN and NVIN are digital codes measured by the ADC at the ADIN and VIN pins, respectively.41511fa13元器件交易网www.cecb2b.com
LTC4151/LTC4151-1PACKAGE DESCRIPTION
DD Package10-Lead Plastic DFN (3mm × 3mm)(Reference LTC DWG # 05-08-1699)R = 0.115TYP60.675±0.05
0.38± 0.10103.50±0.051.65±0.052.15±0.05(2 SIDES)PACKAGEOUTLINE0.25± 0.050.50BSC2.38±0.05(2 SIDES)RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).
CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
PIN 1TOP MARK(SEE NOTE 6)3.00±0.10(4 SIDES)1.65± 0.10(2 SIDES)(DD) DFN 110350.200 REF0.75±0.052.38±0.10(2 SIDES)10.25± 0.050.50 BSC0.00 – 0.05BOTTOM VIEW—EXPOSED PAD
41511fa14元器件交易网www.cecb2b.com
LTC4151/LTC4151-1MS Package10-Lead Plastic MSOP(Reference LTC DWG # 05-08-1661)0.889 ± 0.127(.035 ± .005)5.23(.206)MIN3.20 – 3.45(.126 – .136)3.00 ± 0.102(.118 ± .004)(NOTE 3)0.500.305 ± 0.038(.0197)(.0120 ± .0015)BSCTYP
RECOMMENDED SOLDER PAD LAYOUT
1098760.497 ± 0.076(.0196 ± .003)REF0.254(.010)GAUGE PLANEDETAIL “A”
0° – 6° TYP4.90 ± 0.152(.193 ± .006)3.00 ± 0.102(.118 ± .004)(NOTE 4)123450.53 ± 0.152(.021 ± .006)DETAIL “A”0.18(.007)SEATINGPLANE0.17 – 0.27(.007 – .011)TYP0.1016 ± 0.0508(.004 ± .002)MSOP (MS) 0307 REV E1.10(.043)MAX0.86(.034)REFNOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006\") PER SIDE4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006\") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004\") MAX
0.50(.0197)BSC
41511faInformation furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.15元器件交易网www.cecb2b.com
LTC4151/LTC4151-1TYPICAL APPLICATION
High Side Current, Input Voltage and Open Fuse Monitoringwith a Single LTC4151 F1VIN148VVIN248VD3D4VINR1150kR2301kADINR33.4kGND
41511 TA02
D1D2RS0.02ΩF2SENSE+SENSE–SCLLTC4151I2CSDAADR1ADR0GNDV+LOADV–CONDITIONNADIN ≥ 1.375 • NVIN0.835 • NVIN ≤ NADIN < 1.375 • NVIN0.285 • NVIN ≤ NADIN < 0.835 • NVIN(Not Responding)RESULTNormal OperationF2 is OpenF1 is OpenBoth F1 and F2 are OpenVIN1 and VIN2 are within 20% apart. NADIN and NVIN are digital codes measured by the ADC at the ADIN and VIN pins, respectively.RELATED PARTS
PART NUMBERLTC2451LTC2453LTC2970LTC4215LTC4260LTC4261/LTC4261-2LTC6101/LTC6101HVDESCRIPTION16-Bit I2C Ultra Tiny Delta Sigma ADC16-Bit I2C Ultra Tiny Delta Sigma ADCPower Supply Monitor and Margining ControllerPositive Hot Swap Controller with ADC and I2CCOMMENTSSingle-Ended Input, 0 to VCC Input Range, 60Hz Output Rate, 3mm × 2mm DFN-8 PackageDifferential Input, ±VCC Input Range, 60Hz Output Rate, 3mm × 2mm DFN-8 Package14-Bit ADC Monitoring Current and Voltages, Supplies from 8V to 15V8-Bit ADC Monitoring Current and Voltages, Supplies from 2.9V to 15VPositive High Voltage Hot SwapTM Controller with 8-Bit ADC Monitoring Current and Voltages, Supplies from 8.5V to 80VADC and I2CNegative High Voltage Hot Swap Controller with ADC and I2CHigh Voltage, High Side Current Sense Amplifi er in SOT-23 Package10-Bit ADC Monitoring Current and Voltages, Supplies from –12VSupplies from 4V to 60V (LTC6101) and 5V to 100V (LTC6101HV)Hot Swap and No Latency Delta Sigma are trademarks of Linear Technology Corporation.41511fa16Linear Technology CorporationLT 0109 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com© LINEAR TECHNOLOGY CORPORATION 2008
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