The LDC1101 is a 1.8-V to 3.3-V, high-resolution inductance-to-digital converter for short-range, high-speed, contactless sensing of position, rotation, or motion, enabling reliable, accurate measurements even in the presence of dust or dirt, making it ideal for open or harsh environments.
The LDC1101 features dual inductive measurement cores, allowing for > 150 ksps 16-bit RP and L measurements simultaneous with a high-resolution L measurement which can sample at > 180 ksps with a resolution of up to 24 bits. The LDC1101 includes a threshold-compare function which can be dynamically updated while the device is running.
Inductive sensing technology enables precise measurement of linear/angular position, displacement, motion, compression, vibration, metal composition, and many other applications in markets including automotive, consumer, computer, industrial, medical, and communications. Inductive sensing offers better performance and reliability at lower cost than other, competing solutions.
The LDC1101 offers these benefits of inductive sensing in a small 3-mm × 3-mm 10-pin VSON package. The LDC1101 can be easily configured by a microcontroller using the 4-pin SPI™.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
LDC1101 | VSON (10) | 3.00 mm × 3.00 mm |
Changes from C Revision (February 2016) to D Revision
Changes from B Revision (July 2015) to C Revision
Changes from A Revision (June 2015) to B Revision
Changes from * Revision (May 2015) to A Revision
PIN | TYPE(1) | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
CLDO | 10 | P | Internal LDO bypassing pin. A 15-nF capacitor must be connected from this pin to GND. |
CLKIN | 2 | I | External time-base clock Input |
CSB | 5 | I | SPI CSB. Multiple devices can be connected on the same SPI bus and CSB can be used to uniquely select desired device. CSB must be toggled for proper device operation. |
DAP | – | – | Connect to ground for improved thermal performance(2) |
GND | 8 | G | Ground |
INA | 7 | A | External LC sensor – connect to external LC sensor |
INB | 6 | A | External LC sensor – connect to external LC sensor |
SCLK | 3 | I | SPI clock input |
SDI | 4 | I | SPI data input – connect to MOSI of SPI master |
SDO/INTB | 1 | O | SPI data output/INTB – Connect to MISO of SPI master. When CSB is high, this pin is High-Z. Alternatively, this pin can be configured to function as INTB |
VDD | 9 | P | Power supply |
MIN | MAX | UNIT | ||
---|---|---|---|---|
VDD | Supply voltage range | 3.6 | V | |
Vi | Voltage on INA, INB | –0.3 | 2.3 | V |
Voltage on CLDO | –0.3 | 1.9 | V | |
Voltage on any other pin(2) | –0.3 | VDD + 0.3 | V | |
TJ | Junction temperature | –55 | 125 | °C |
Tstg | Storage temperature | –65 | 125 | °C |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) | ±2000 | V |
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) | ±1000 |
MIN | NOM | MAX | UNIT | ||
---|---|---|---|---|---|
VDD | Supply voltage | 1.71 | 3.46 | V | |
TJ | Junction temperature | –40 | 125 | °C |
THERMAL METRIC(1) | LDC1101 | UNIT | |
---|---|---|---|
DRC (VSON) | |||
10 PINS | |||
RθJA | Junction-to-ambient thermal resistance | 44.2 | °C/W |
RθJC(top) | Junction-to-case (top) thermal resistance | 50.1 | °C/W |
RθJB | Junction-to-board thermal resistance | 19.6 | °C/W |
ψJT | Junction-to-top characterization parameter | 0.7 | °C/W |
ψJB | Junction-to-board characterization parameter | 19.8 | °C/W |
RθJC(bot) | Junction-to-case (bottom) thermal resistance | 4.4 | °C/W |
PARAMETER | TEST CONDITION(1) | MIN(2) | TYP(3) | MAX(2) | UNIT | |
---|---|---|---|---|---|---|
POWER | ||||||
VDD | Supply voltage | 1.71 | 3.46 | V | ||
IDD | Supply current | START_CONFIG= 0x00, no sensor connected | 1.9 | 2.7 | mA | |
IDDS | Supply current including sensor current | ƒCLKIN = 16 MHz, ƒSENSOR = 2 MHz, START_CONFIG = 0x00 |
3.2 | mA | ||
IDDSL | Sleep mode supply current | START_CONFIG =0x01 | 135 | 180 | µA | |
ISD | Shutdown mode supply current | 1.4 | 6.7 | µA | ||
SENSOR | ||||||
RP Measurement part-to-part variation | RESP_TIME= 6144, D_CONFIG=0x00, ALT_CONFIG=0x00, START_CONFIG = 0x00, ƒSENSOR = 2 MHz | 1% | ||||
ISENSORMAX | Sensor maximum current drive | RP_MIN = b111, START_CONFIG=0x00, D_CONFIG=0x00, ALT_CONFIG=0x00 | 0.598 | 0.6 | 0.602 | mA |
ISENSORMIN | Sensor minimum current drive | RP_MAX = b000, HIGH_Q_SENSOR=b0, START_CONFIG=0x00, D_CONFIG=0x00, ALT_CONFIG=0x00 | 4.7 | µA | ||
ƒSENSOR | Sensor resonant frequency | Device settings and Sensor compliant as detailed in LDC1101 RP Configuration | 0.5 | 10 | MHz | |
RPRES | RP Measurement resolution | 16 | bits | |||
LRES | Inductance sensing resolution – RP+L Mode | 16 | bits | |||
Inductance sensing resolution – LHR Mode | 24 | bits | ||||
AOSC | Sensor oscillation amplitude | INA – INB, START_CONFIG=0x00, D_CONFIG=0x00, ALT_CONFIG=0x00 | 1.2 | VPP | ||
DETECTION | ||||||
tS_MIN | Minimum response time (RP+L mode) | RP+L Mode, RESP_TIME=b010 | 192 ÷ ƒSENSOR |
s | ||
tS_MAX | Maximum response time (RP+L mode) | RP+L Mode, RESP_TIME=b111 | 6144 ÷ ƒSENSOR |
s | ||
Ts_MAX | High Res L maximum measurement interval | LHR_REF_COUNT=0xFFFF, START_CONFIG=0x00 | (220+39) ÷ ƒCLKIN |
s | ||
SRMAXRP | RP+L Mode maximum sample rate | ƒCLKIN=16 MHz, ƒSENSOR = 10 MHz, RESP_TIME=b010 | 156.25 | kSPS | ||
SRMAXL | High Res L Mode maximum sample rate | High Resolution L Mode, LHR_REF_COUNT=0x0002, ƒCLKIN=16 MHz | 183.8 | kSPS | ||
FREQUENCY REFERENCE | ||||||
fCLKIN | Reference input frequency | 1 | 16 | MHz | ||
DCfin | Reference duty cycle | 40% | 60% | |||
VIH | Input high voltage (Logic “1”) | 0.8 × VDD | V | |||
VIL | Input low voltage (Logic “0”) | 0.2 × VDD | V |
PARAMETER | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|
VOLTAGE LEVELS | |||||
VIH | Input high voltage (Logic “1”) | 0.8 × VDD | V | ||
VIL | Input low voltage (Logic “0”) | 0.2 × VDD | V | ||
VOH | Output high voltage (Logic “1”, ISOURCE = 400 µA) | VDD– 0.3 | V | ||
VOL | Output low voltage (Logic “0”, ISINK = 400 µA) | 0.3 | V | ||
IOHL | Digital IO leakage current | –500 | 500 | nA |
MIN | NOM | MAX | UNIT | ||
---|---|---|---|---|---|
tSTART | Start-up time from shutdown to sleep | 0.8 | ms | ||
tWAKE | Wake-up time (from completion of SPI to conversion start; does not include sensor settling time) | 0.04 | ms | ||
INTERFACE TIMING REQUIREMENTS(1) | |||||
ƒSCLK | Serial clock frequency | 8 | MHz | ||
twH | SCLK pulse-width high | 0.4/ƒSCLK | s | ||
twL | SCLK pulse-width low | 0.4/ƒSCLK | s | ||
tsu | SDI setup time | 10 | ns | ||
th | SDI hold time | 10 | ns | ||
tODZ | SDO driven-to-tristate time | 25 | ns | ||
tOZD | SDO tristate-to-driven time | 25 | ns | ||
tOD | SDO output delay time | 20 | ns | ||
tsu(CS) | CSB setup time | 20 | ns | ||
th(CS) | CSB hold time | 20 | ns | ||
tIAG | CSB inter-access interval | 100 | ns | ||
tw(DRDY) | Data ready pulse width | 1/ƒSENSOR | ns |
Not including sensor current, default register settings. |
Including sensor current. 13-mm diameter sensor 0.1-mm spacing/0.1-mm trace width/ 4-layer 28 turns, fSENSOR = 2 MHz, RP_SET = 0x07, TX1 = 0x50, TC2 = 0x80, RCOUNT = 0xFFFF, RESP_TIME = 6144 |
RP_SET.RPMAX = b000 |
Not including sensor current, default register settings. |
RP_SET.RPMIN = b111 |