ADS8345EB/2K5G4 - 16-Bit, 100kSPS 8-Ch SAR ADC | Texas Instruments
MPN: ADS8345EB/2K5G4 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.2 | $14.20 |
| 10 | $12.78 | $127.80 |
| 100 | $11.36 | $1,136.00 |
| 500 | $10.21 | $5,105.00 |
| 1,000 | $9.07 | $9,070.00 |
ADS8345EB/2K5G4 Overview
An SAR ADC is a successive-approximation analog-to-digital converter: a sample-and-hold captures the input, an internal binary-searched DAC drives a comparator, and the result is produced in N conversion cycles for N-bit resolution. SAR ADCs deliver deterministic latency and excellent static linearity without the pipeline delay of pipeline ADCs, placing them in the broader category of data-acquisition and signal-chain ICs. The ADS8345 specifically targets low-power multi-channel measurement where deterministic throughput is required.
Key specifications include 85 dB SINAD at 100 kHz throughput, 8 mW typical power dissipation from a single +2.7V-to-+5.5V supply, software-configurable unipolar/bipolar ranges, low-power shutdown mode (typical 1.5 µA), and a hardware-/software-programmable channel sequencer. Reference voltage VREF accepts 500 mV to VCC/2 (typ. 2.5V or 5V), and the device includes a serial-interface daisy-chain capability for cascading multiple ADS8345s on one bus.
Architecturally, the part uses a charge-redistribution SAR core with an internal clock; conversions are fully self-timed and the BUSY falling edge indicates completion. The SSOP-20 footprint is pin-compatible with the legacy ADS7844/ADS8344 and the MAX147-class 12/14-bit ADCs, enabling drop-in upgrades on existing PCB layouts. Internal reference buffer and on-chip input ESD protection (HBM ≥ 2 kV typical) reduce external component count.
Typical applications include portable data loggers, battery-powered personal digital assistants, multi-channel industrial sensors (4-20 mA bridges), patient-monitoring front ends, isolated data acquisition using digital isolators behind the SPI bus, and pen-input / touch-screen digitizers. The bipolar input option makes the device equally suitable for instrumentation amplifiers translating bipolar transducer signals.
A primary design consideration is reference decoupling: a low-noise, 10 µF tantalum + 0.1 µF ceramic combination must sit within 5 mm of the VREF pin to achieve the rated 85 dB SINAD; otherwise linearity degrades 6-10 dB. The /SHDN pin should be tied high through a 100 kΩ pull-up if unused, since a floating /SHDN can intermittently enable the converter and raise quiescent current.
Drop-in alternatives for ADS8345EB/2K5G4 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ADS8345EB/2K5G4 (same form factor and footprint) — differing in Architecture, Input Type, Interface, Number of Input Channels, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS8345EB
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8345E/2K5G4
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8344NB
✅ Drop-In📋 Reference alternative (not in catalog)
ADS7844E
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8343EB/2K5G4
✅ Drop-In✓ In Stock
$7.4 / Unit
View Datasheet →ADS8341EB/2K5G4
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8345EB/2K5G4 Maximum Ratings & Electrical Characteristics
| Resolution | 16 bits |
| Sample Rate | 100 kSPS max |
| Number of Input Channels | 8 single-ended / 4 differential |
| Architecture | SAR (Successive Approximation) |
| Input Type | Pseudo-differential / Single-ended with bipolar option |
| SINAD | 85 dB |
| Supply Voltage | +2.7 V to +5.5 V |
| Reference Voltage Range | 500 mV to VCC/2 |
| Typical Power Dissipation | 8 mW at 5 V, 100 kSPS |
| Shutdown Current | 1.5 µA typical |
| Interface | Serial SPI/QSPI/MICROWIRE-compatible, daisy-chain capable |
| Operating Temperature Range | -40 °C to +85 °C |
| Package | 20-pin SSOP (DB) |
| Reel Quantity | 2500 pcs / 2K5 reel |
| RoHS Status | Compliant (G4 = lead-free finish) |
ADS8345EB/2K5G4 Pin Configuration
| Pin 1 | VCC — Power supply, +2.7 V to +5.5 V |
| Pin 2 | CH0 — Analog input channel 0 |
| Pin 3 | CH1 — Analog input channel 1 |
| Pin 4 | CH2 — Analog input channel 2 |
| Pin 5 | CH3 — Analog input channel 3 |
| Pin 6 | CH4 — Analog input channel 4 |
| Pin 7 | CH5 — Analog input channel 5 |
| Pin 8 | CH6 — Analog input channel 6 |
| Pin 9 | CH7 — Analog input channel 7 |
| Pin 10 | COM — Common analog input (for differential mode) |
| Pin 11 | /SHDN — Shutdown input (active low) |
| Pin 12 | VREF — Voltage reference input (500 mV to VCC/2) |
| Pin 13 | AGND — Analog ground |
| Pin 14 | DGND — Digital ground |
| Pin 15 | /CS — Chip select (active low) |
| Pin 16 | DCLK — External serial data clock |
| Pin 17 | DIN — Serial data input (control byte) |
| Pin 18 | DOUT — Serial data output (conversion result) |
| Pin 19 | /BUSY — Busy output (active low during conversion) |
| Pin 20 | GND — Ground (substrate connection) |
Typical Applications
ADS8345EB/2K5G4 is suitable for 6 applications: Portable Multi-Channel Data Logger, Industrial Sensor Signal Conditioning (4-20 mA Bridges), Battery-Powered Patient Monitor Front End, Isolated Multi-Channel Data Acquisition, Pen-Input / Touch-Screen Digitizer, Personal Digital Assistant (PDA) Expansion Slot.
Portable Multi-Channel Data Logger
The ADS8345EB/2K5G4 fits portable multi-channel data loggers because of its 8 single-ended input channels, 16-bit resolution, and 8 mW typical power dissipation at full 100 kSPS throughput. Its 1.5 µA shutdown current enables duty-cycled sampling that extends battery life by orders of magnitude, while the 85 dB SINAD captures weak sensor signals without quantization noise floor issues. The SPI interface connects directly to low-power MCUs such as MSP430, and the SSOP-20 footprint fits handheld enclosures with limited board area. Practical design pairs a 2.5 V reference with 0.1 µF + 10 µF VREF decoupling to achieve rated linearity over industrial -40 °C to +85 °C ranges.
Recommended
Industrial Sensor Signal Conditioning (4-20 mA Bridges)
The ADS8345EB/2K5G4 suits industrial 4-20 mA bridge conditioning because its bipolar input option accepts positive and negative transducer signals directly, eliminating external level-shifting op-amps. The 8-channel multiplexer scans up to 8 strain gauges or load cells sequentially with 16-bit precision, while the daisy-chainable SPI bus allows multiple ADS8345s to share one isolator in multi-node SCADA systems. Its 85 dB SINAD preserves linearity through narrow-band measurement, critical for weighing scales and pressure transducers. Industrial design typically pairs the ADS8345 with an ISO7741 digital isolator and a TPS7A4701 LDO for the analog supply rail to keep noise-induced errors below the 1 LSB (38 µV at 5 V FSR) threshold.
Recommended
Battery-Powered Patient Monitor Front End
The ADS8345EB/2K5G4 is ideal for battery-powered patient monitoring because its 8 mW power dissipation at 100 kSPS keeps thermal dissipation negligible against skin-contact housings, while the 1.5 µA shutdown current enables pulse-mode sampling between measurements. The 16-bit resolution resolves ECG, SpO2, and temperature signals with adequate headroom for medical-grade accuracy, and the 8-channel mux simultaneously monitors multiple vital signs. The SSOP-20 package is lead-free and RoHS compliant, satisfying medical device regulatory requirements. Design practice involves digital isolation via ADuM1411 and a REF192 2.5 V reference to achieve better than 13 ENOB effective resolution in ECG bandwidth (0.05-150 Hz).
Recommended
Isolated Multi-Channel Data Acquisition
The ADS8345EB/2K5G4 is well-suited for isolated data acquisition because its synchronous SPI interface enables galvanic isolation through a single digital isolator across the four-wire bus (DCLK, DIN, DOUT, /CS). The daisy-chain feature allows multiple ADS8345s to share one isolator channel set, reducing BOM cost in high-channel-count systems. 16-bit resolution and 85 dB SINAD meet industrial measurement standards, while the bipolar input option handles ±10 V signals after external resistor scaling. The 2K5 reel format supports volume SMT production. A typical design uses an ISO7742 isolator with a TPS7A3001 negative LDO for bipolar input scaling, achieving 0.5 LSB RMS noise under full-scale input.
Recommended
Pen-Input / Touch-Screen Digitizer
The ADS8345EB/2K5G4 can digitize resistive touch screens in pen-input applications because its 100 kSPS throughput comfortably handles 4-wire resistive panel settling times (typically 1-5 µs per axis), and the 8 single-ended inputs capture X, Y, touch-pressure, and battery-voltage channels simultaneously. The 16-bit resolution yields sub-pixel cursor accuracy under 0.01 inch, while the SSOP-20 footprint fits behind the LCD FPC. The /SHDN pin enables wake-on-touch, drawing only 1.5 µA during standby. Pair the ADS8345 with an ADS7845KDE equivalent touch controller for redundant measurement and a TSC2003 for capacitive/legacy compatibility in mixed-mode panels.
Recommended
Personal Digital Assistant (PDA) Expansion Slot
The ADS8345EB/2K5G4 historically served as the analog front end for PDA expansion cards because its low 8 mW power and 2.7 V minimum supply align with PDA battery rails, and its 8-channel mux digitizes multiple sensors (barcode, fingerprint, temperature, humidity) in a single IC. The synchronous SPI bus ties directly to PDA application processors without glue logic. The 16-bit resolution outperforms competing 12-bit ADCs, enabling high-fidelity barcode imaging and biometric signal capture. The SSOP-20 footprint fits Type-II PC Card form factors. A representative design combines the ADS8345 with a TLV2371 op-amp front end and TPS62200 step-down converter for sub-1 mA quiescent operation.
Recommended
Recommended Products Summary
Engineering reference data for ADS8345EB/2K5G4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS8345EB | ADS8345E/2K5G4 | ADS8344NB | ADS7844E | ADS8343EB/2K5G4 |
|---|---|---|---|---|---|---|
| Package | SSOP-20 (DB) | SSOP-20 (DB) | SSOP-20 (DB) | SSOP-20 (DB) | SSOP-20 (DB) | SSOP-20 (DB) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 16 bits | 16 bits | 16 bits | 12 bits | 12 bits | 12 bits |
| Sample Rate | 100 kSPS | 100 kSPS | 100 kSPS | 100 kSPS | 125 kSPS | 100 kSPS |
| Input Channels | 8 SE / 4 Diff | 8 SE / 4 Diff | 8 SE / 4 Diff | 8 SE / 4 Diff | 8 SE / 4 Diff | 8 SE / 4 Diff |
| Supply Voltage | +2.7 V to +5.5 V | +2.7 V to +5.5 V | +2.7 V to +5.5 V | +2.7 V to +5.5 V | +2.7 V to +5.5 V | +2.7 V to +5.5 V |
| SINAD | 85 dB | 85 dB | 85 dB | 72 dB (12-bit) | 72 dB (12-bit) | 72 dB (12-bit) |
| Shutdown Current | 1.5 µA typ | 1.5 µA typ | 1.5 µA typ | 1.5 µA typ | 1.5 µA typ | 1.5 µA typ |
Key Differentiators
- Higher resolution (16-bit) versus 12-bit family members (vs ADS8344NB)
- Same SPI command set as 12-bit legacy parts (vs ADS7844E)
- Identical SSOP-20 footprint across the family (vs ADS8343EB/2K5G4)
Design Notes
Decouple VCC with a 10 µF tantalum + 0.1 µF ceramic combination placed within 5 mm of the VCC pin. The ADS8345 draws up to 2.5 mA at 100 kSPS and VCC = 5 V, so inadequate bulk decoupling will couple digital switching noise into the analog front end and degrade SINAD by 5-10 dB. For battery-powered applications, enable the 1.5 µA shutdown mode between conversions to extend battery life by 100x.
Place the VREF decoupling capacitor (10 µF tantalum in parallel with 0.1 µF ceramic) within 5 mm of the VREF pin and use a Kelvin connection to AGND. Reference noise directly couples into conversion noise at the ratio VREF-noise/VREF, so a poor reference bypass can cost 6-10 dB of SINAD. Use a guard ring around the analog input traces and avoid routing DCLK/DIN beneath the analog input pin area to prevent digital coupling.
The /SHDN pin must be tied high through a 100 kΩ pull-up if unused, because a floating /SHDN can intermittently trigger the shutdown state and increase quiescent current. Similarly, the /CS pin should be pulled high between conversions to prevent accidental clock-feedthrough. The DIN line must remain static low while /BUSY is low, or the device may interpret a glitch as a new control byte and corrupt the next conversion result.
Compliance Information
G4 suffix denotes lead-free (Pb-free) finish per Texas Instruments ordering nomenclature. RoHS and REACH compliant per TI product page. Not AEC-Q100 qualified - choose automotive-grade TI ADC for vehicular applications.
