# AD7746ARUZ

**Analog Devices** · Pre-ordered Chips · TSSOP-16

AD7746ARUZ from Analog Devices, in a TSSOP-16. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | SCL | input | Serial interface clock input connected to the master clock line, requiring a pull-up resistor if the system does not provide one. |
| 2 | RDY | output | Logic output that falls to indicate a finished conversion on the enabled channel(s), and may be left as an open circuit if unused. |
| 3 | EXCA | output | CDC excitation output; the measured capacitance is connected between one EXC pin and one CIN pin, and it may be left open if unused. |
| 4 | EXCB | output | CDC excitation output; the measured capacitance is connected between one EXC pin and one CIN pin, and it may be left open if unused. |
| 5 | REFIN(+) | input | Positive differential voltage reference input for the voltage channel (ADC), which is not used by the capacitive channels and may be left open or tied to GND if unused. |
| 6 | REFIN(-) | input | Negative differential voltage reference input for the voltage channel (ADC), which is not used by the capacitive channels and may be left open or tied to GND if unused. |
| 7 | CIN1(-) | input | Negative capacitive input in differential mode, internally disconnected in single-ended CDC configuration, and may be left open or tied to GND if unused. |
| 8 | CIN1(+) | input | Capacitive input in single-ended mode or positive capacitive input in differential mode, connected between one EXC pin and one CIN pin, and may be left open or tied to GND if unused. |
| 9 | CIN2(+) | input | Second capacitive input in single-ended mode or positive capacitive input in differential mode, and may be left open or tied to GND if unused. |
| 10 | CIN2(-) | input | Negative capacitive input in differential mode, internally disconnected in single-ended CDC configuration, and may be left open or tied to GND if unused. |
| 11 | VIN(+) | power_in | Positive differential voltage input for the voltage channel (ADC), also used to connect an external temperature sensing diode, and may be left open or tied to GND if unused. |
| 12 | VIN(-) | power_in | Negative differential voltage input for the voltage channel (ADC), also used to connect an external temperature sensing diode, and may be left open or tied to GND if unused. |
| 13 | GND | power_in | Ground pin for the device. |
| 14 | VDD | power_in | Power supply pin, to be decoupled to GND with a low impedance capacitor such as a 10 µF tantalum in parallel with a 0.1 µF multilayer ceramic; the datasheet specifies 2.7 V to 5.25 V single-supply operation. |
| 15 | NC | unconnected | Not connected; this pin should be left as an open circuit. |
| 16 | SDA | bidirectional | Serial interface bidirectional data line connected to the master data line, requiring a pull-up resistor if the system does not provide one. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices |
| Package | TSSOP-16 |
| Category | Interface ICs |
| Pins | 16 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Integral Nonlinearity (INL) |  | -0.01 |  | 0.01 | % of FSR |  | 3 |
| Absolute Error |  | -4 |  | 4 | fF | 25°C, VDD = 5 V, after offset calibration | 3 |
| Gain Drift vs. Temperature |  | -28 | -26 | -24 | ppm of FS/°C |  | 3 |
| CAPDAC Drift vs. Temperature |  | 24 | 26 | 28 | ppm of FS/°C |  | 3 |
| System Offset Calibration Range |  | -1 |  | 1 | pF |  | 3 |
| Offset Error |  | -3 |  | 3 | µV | Voltage input | 3 |
| Gain Error |  |  | 0.02 | 0.08 | % of FS | 25°C, VDD = 5 V | 3 |
| Allowed Capacitance to GND |  |  |  | 60 | pF | See Figure 9 and Figure 10 | 3 |
| Allowed Capacitance to GND |  |  |  | 100 | pF | See Figure 11 | 3 |
| Average DC Voltage Across Capacitance |  |  |  | 40 | mV | Magnitude below ±40 mV | 3 |
| Full-Scale Error |  |  | 0.025 | 0.1 | % of FS | Voltage input | 3 |
| Internal Temperature Sensor Error |  |  | 0.5 | 2 | °C | Internal temperature sensor | 3 |
| External Sensing Diode Error |  | -2 |  | 2 | °C | External sensing diode | 3 |
| Absolute VIN Voltage |  | -0.03 |  |  | V | Relative to GND; upper limit printed as VDD + 0.03 V | 3 |
| Power Supply Rejection |  |  | 0.3 | 1 | fF/V |  | 3 |
| Full Range CAPDAC |  |  | 17 | 21 | pF |  | 3 |
| Integral Nonlinearity (INL) voltage input |  |  | 3 | 15 | ppm of FS | Voltage input | 3 |
| SCL Frequency |  | 0 |  | 400 | kHz | See Figure 3 | 5 |
| SCL High Pulse Width | tHIGH | 0.6 |  |  | µs |  | 5 |
| SCL Low Pulse Width | tLOW | 1.3 |  |  | µs |  | 5 |
| SCL, SDA Rise Time | tR |  |  | 0.3 | µs |  | 5 |
| SCL, SDA Fall Time | tF |  |  | 0.3 | µs |  | 5 |
| Hold Time (Start Condition) | tHD;STA | 0.6 |  |  | µs | After this period, the first clock is generated | 5 |
| Set-Up Time (Start Condition) | tSU;STA | 0.6 |  |  | µs | Relevant for repeated start condition | 5 |
| Data Set-Up Time | tSU;DAT | 0.25 |  |  | µs | VDD ≥ 3.0 V | 5 |
| Data Set-Up Time | tSU;DAT | 0.35 |  |  | µs | VDD < 3.0 V | 5 |
| Set-Up Time (Stop Condition) | tSU;STO | 0.6 |  |  | µs |  | 5 |
| Data Hold Time (Master) | tHD;DAT | 0 |  |  | µs |  | 5 |
| Bus-Free Time (Between Stop and Start Condition) | tBUF | 1.3 |  |  | µs |  | 5 |
| Positive Supply Voltage VDD to GND |  | -0.3 |  | 6.5 | V |  | 6 |
| Voltage on any Input or Output Pin to GND |  | -0.3 |  |  | V | Upper limit printed as VDD + 0.3 V | 6 |
| Operating Temperature Range |  | -40 |  | 125 | °C |  | 6 |
| Storage Temperature Range |  | -65 |  | 150 | °C |  | 6 |
| Junction Temperature |  |  |  | 150 | °C |  | 6 |
| Lead Temperature, Soldering Vapor Phase |  |  |  | 215 | °C | 60 sec | 6 |
| Lead Temperature, Soldering Infrared |  |  |  | 220 | °C | 15 sec | 6 |
| ESD Rating (Human Body Model) |  |  |  | 2000 | V | ESD Association HBM, S5.1 | 6 |
| TSSOP Thermal Impedance-to-Air | θJA |  | 128 |  | °C/W |  | 6 |
| TSSOP Thermal Impedance-to-Case | θJC |  | 14 |  | °C/W |  | 6 |
| Offset Drift vs. Temperature |  |  | -1 |  | aF/°C |  | 3 |
| Resolution, p-p |  |  | 16.5 |  | Bit | Conversion time = 62 ms | 3 |
| Resolution Effective |  |  | 19 |  | Bit | Conversion time = 62 ms | 3 |
| No Missing Codes |  |  | 24 |  | Bit | Conversion time ≥ 62 ms | 3 |
| Output Noise, rms |  |  | 2 |  | aF/√Hz | See Table 5 | 3 |
| Offset Error |  |  | 32 |  | aF | After system offset calibration, excluding effect of noise | 3 |
| Normal Mode Rejection |  |  | 65 |  | dB | 50 Hz ± 1%, conversion time = 62 ms | 3 |
| Normal Mode Rejection |  |  | 55 |  | dB | 60 Hz ± 1%, conversion time = 62 ms | 3 |
| Channel-to-Channel Isolation |  |  | 70 |  | dB | AD7746 only | 3 |
| CAPDAC Resolution |  |  | 164 |  | fF | 7-bit CAPDAC | 3 |
| Excitation Frequency |  |  | 32 |  | kHz |  | 3 |
| Temperature Sensor Resolution |  |  | 0.1 |  | °C | VREF internal | 3 |
| Offset Drift vs. Temperature (voltage input) |  |  | 15 |  | nV/°C | Voltage input | 3 |

## CAD (KiCad official)

- Symbol: `AD7746ARUZ`
- Footprint: `Package_SO:TSSOP-16_4.4x5mm_P0.65mm`
- 3D model: TSSOP-16 (KiCad packages3D, STEP)
- 3D model files: `ad7746aruz-etched.step` / `ad7746aruz-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ad7746aruz.step` / `ad7746aruz.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Analog Devices datasheet](https://www.analog.com/media/en/technical-documentation/data-sheets/AD7745_7746.pdf) (28 pp, sha256 `567331d82161a3f1`, retrieved 2026-11-02, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/ad7746aruz-datasheet.pdf)