ADS8345NB/1K - 16-Bit 8-Ch 100kSPS SAR ADC | Texas Instruments
MPN: ADS8345NB/1K ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $13.05 | $130.50 |
| 100 | $11.6 | $1,160.00 |
| 500 | $10.44 | $5,220.00 |
| 1,000 | $9.28 | $9,280.00 |
| 2,500 | $7.85 | $19,625.00 |
ADS8345NB/1K Overview
A SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary-search algorithm against an internal precision DAC and a comparator to resolve analog inputs one bit per conversion clock cycle; SAR ADCs sit within the broader hierarchy of analog-to-digital converters -> data converters -> signal chain ICs -> semiconductor. SAR architectures are widely preferred when deterministic latency, low latency, and excellent DC accuracy are required, as opposed to delta-sigma converters which trade speed for resolution. The ADS8345NB/1K's 100 kSPS maximum sample rate and 85 dB SINAD place it firmly in the category of mid-speed, high-accuracy precision measurement ADCs.
Key features include 100 kSPS maximum sampling rate, 85 dB SINAD, a low-power shutdown mode, an input range selectable from 0 V to VREF (unipolar) or ±VREF (bipolar) with VREF settable from 500 mV to +VCC/2, and SPI/QSPI/MICROWIRE-compatible serial interface. Channel selection is controlled through a 3-bit address field, and an on-chip CONVST signal initiates conversions independently of the read cycle, simplifying trigger and synchronization designs. The device operates over -40 °C to +85 °C industrial temperature range and is offered in QSOP-20 and SSOP-20 packages.
The ADS8345NB/1K's onboard 8-channel multiplexer and serial interface remove the need for external analog switches or parallel bus buffers, reducing PCB area and total BOM cost. Compared with first-generation ADS7844/ADS8344 devices, the ADS8345 maintains full pin-to-pin compatibility while improving noise performance and adding a hardware shutdown pin for power-constrained applications. Designers commonly use the part in 4-wire resistive touchscreens, multi-cell battery monitors, and isolated data-acquisition front-ends where its serial interface couples cleanly to digital isolators.
Typical applications include portable multi-channel data loggers, personal digital assistants, industrial process control instrumentation, and remote data acquisition modules. The combination of 8 channels and 16-bit resolution makes the part attractive where multiple sensors must share a single ADC to minimize cost and controller pin count, with channel cycling handled in firmware.
When designing with the ADS8345NB/1K, ensure VREF is well-bypassed with a 10 µF tantalum or ceramic capacitor in parallel with a 0.1 µF ceramic, and keep analog/digital grounds separated back at a single star point to preserve the 85 dB SINAD figure. Decouple both AVDD and DVDD pins individually, and route the analog inputs away from switching traces or clocks to avoid coupling noise into the comparator.
This page synthesizes distributor pricing, drop-in same-package and cross-package alternatives, and practical design notes not found in the manufacturer datasheet alone, providing engineers with a single decision-ready reference.
Drop-in alternatives for ADS8345NB/1K — 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 ADS8345NB/1K (same form factor and footprint) — differing in Input Type, Package, SINAD, Architecture, Interface.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS8345NB
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8345NB/1KG4
✅ Drop-In✓ In Stock
$4.92 / Unit
View Datasheet →ADS8344N
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8343EB/2K5G4
✅ Drop-In✓ In Stock
$7.4 / Unit
View Datasheet →ADS8344NB/1K
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8345NB/1K Maximum Ratings & Electrical Characteristics
| Resolution | 16 bits |
| Number of Channels | 8 single-ended / 4 differential |
| Conversion Architecture | Successive Approximation Register (SAR) |
| Maximum Sample Rate | 100 kSPS |
| Input Type | Bipolar / Unipolar, single-ended or fully differential |
| Analog Input Range | 0 V to VREF (unipolar) or ±VREF (bipolar) |
| Reference Voltage (VREF) Range | 500 mV to VCC/2 |
| Analog Supply Voltage (AVDD) | 2.7 V to 5.25 V |
| Digital Supply Voltage (DVDD) | 1.5 V to 5.25 V |
| SINAD | 85 dB |
| Typical Power Dissipation | 8 mW at 100 kSPS, +5 V supply |
| Shutdown Current | < 1 µA (typ) |
| Digital Interface | Synchronous Serial (SPI / QSPI / MICROWIRE compatible) |
| Operating Temperature Range | -40 °C to +85 °C |
| Package | 20-SSOP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Reel Quantity | 1000 (per /1K suffix) |
ADS8345NB/1K Pin Configuration
| Pin 1 | +VREF — Reference voltage input (500 mV to VCC/2) |
| Pin 2 | IN0 — Analog input channel 0 (single-ended) or +IN0 (differential) |
| Pin 3 | IN1 — Analog input channel 1 (single-ended) or -IN0 (differential) |
| Pin 4 | IN2 — Analog input channel 2 (single-ended) or +IN1 (differential) |
| Pin 5 | IN3 — Analog input channel 3 (single-ended) or -IN1 (differential) |
| Pin 6 | IN4 — Analog input channel 4 (single-ended) or +IN2 (differential) |
| Pin 7 | IN5 — Analog input channel 5 (single-ended) or -IN2 (differential) |
| Pin 8 | IN6 — Analog input channel 6 (single-ended) or +IN3 (differential) |
| Pin 9 | IN7 — Analog input channel 7 (single-ended) or -IN3 (differential) |
| Pin 10 | AGND — Analog ground |
| Pin 11 | SCLK — Serial clock input (SPI) |
| Pin 12 | DOUT — Serial data output (SPI MISO) |
| Pin 13 | DIN — Serial data input (SPI MOSI) |
| Pin 14 | CS — Chip select (active low) |
| Pin 15 | BUSY — Conversion in progress (active high) |
| Pin 16 | CONVST — Conversion start input (active low) |
| Pin 17 | AVDD — Analog supply voltage (+2.7 V to +5.25 V) |
| Pin 18 | DVDD — Digital supply voltage (+1.5 V to +5.25 V) |
| Pin 19 | DGND — Digital ground |
| Pin 20 | SHDN — Hardware shutdown (active low, < 1 µA quiescent) |
Typical Applications
ADS8345NB/1K is suitable for 6 applications: Portable Multi-Channel Data Logger, Personal Digital Assistant (PDA) and Handheld Terminal, Isolated Multi-Channel Data Acquisition Module, Industrial Process Control Instrumentation, Battery Management and Multi-Cell Voltage Monitor, Remote Sensor Front-End and Test Equipment.
Portable Multi-Channel Data Logger
The ADS8345NB/1K's 8 input channels, 16-bit resolution and 100 kSPS throughput let a single device digitize up to 8 thermocouple, strain-gauge, or transducer signals in a battery-powered data logger, reducing BOM count and PCB area. According to the TI datasheet, the shutdown mode drops quiescent current below 1 µA between conversion bursts, which is critical for multi-month field deployments where total energy budget is dominated by sleep current. Place the ADC on a dedicated analog island with a star-ground tie-back and power it from a low-noise LDO such as the TPS7A4701 to preserve the 85 dB SINAD figure; run the SPI bus at the lowest viable SCLK to avoid digital switching noise coupling into the analog inputs. Channel cycling is performed in firmware, so the same firmware tree can scale to 16 or more channels by adding a second identical part on a different SPI /CS line.
Recommended
Personal Digital Assistant (PDA) and Handheld Terminal
PDA-class and handheld-terminal designs historically relied on the ADS8345NB/1K for low-power multi-source sampling of stylus position, battery monitor, ambient light, and temperature sensors. With 8 single-ended inputs, the device eliminates an external analog switch matrix that would otherwise cost board area and quiescent current. The 16-bit result and 85 dB SINAD support pen-position tracking to sub-1 % of full-scale range when paired with a 4-wire resistive touchscreen, while shutdown mode between scans keeps average current below 100 µA. For PDA layouts, route SCLK and DIN/DOUT over a ground-guard trace and keep the analog input traces matched in length to preserve common-mode rejection. The 20-SSOP footprint is small enough to fit beneath most 5 mm × 5 mm shielding cans, simplifying EMI containment.
Recommended
Isolated Multi-Channel Data Acquisition Module
Because the ADS8345NB/1K uses a synchronous serial interface, it pairs naturally with digital isolators (e.g., ISO7641) to build a 4 kV-isolated 8-channel data acquisition module for industrial sensor arrays and shunt-resistor current monitoring. The serial data, clock, and CS lines all cross the isolation barrier with no parallel-bus penalty, minimizing the isolator channel count to 3. The ADS8345NB/1K's 16-bit resolution and 100 kSPS sample rate comfortably handle CT (current transformer) and PT (potential transformer) outputs of up to 1 kHz bandwidth while preserving ±0.05 % measurement accuracy. Use a separate isolated DC-DC converter (e.g., SN6501 + transformer) on the field side to keep the analog and digital grounds truly galvanically isolated, and place a 10 µF X7R bypass right at the AVDD pin. Reference design checklists should verify that the chosen isolator supports the full 2.5 MHz / 4.5 MHz SCLK range required by the device at full 100 kSPS throughput.
Recommended
Industrial Process Control Instrumentation
In PLC analog input modules and process control instrumentation, the ADS8345NB/1K's bipolar ±VREF input range and 85 dB SINAD support direct interfacing to 4–20 mA current-loop-derived voltage signals and thermocouple outputs without instrumentation amplifiers. The 8 channels per IC allow a single part to replace four discrete ADCs in a typical 16-channel PLC card, halving PCB area and quiescent current. The -40 °C to +85 °C operating range covers most industrial cabinet environments without derating. Place an external low-noise reference such as REF5045 with Kelvin-sensing traces to the ADS8345NB/1K VREF and AGND pins, and put a 0.1 µF + 10 µF X7R bypass network right at the converter to hold dynamic accuracy over SCLK switching events. Most PLC firmware already runs an SPI master, so the ADS8345NB/1K integrates without new driver code.
Recommended
Battery Management and Multi-Cell Voltage Monitor
For multi-cell battery monitors, the ADS8345NB/1K can digitize up to 8 individual cell voltages or pack-level currents through a resistor-divider network, providing ±0.05 % measurement accuracy at 16-bit resolution. The shutdown pin is directly usable to coordinate conversion timing with the system's main buck converter, dropping ADC quiescent current to sub-1 µA between scans. With the bipolar input configuration and VREF tied to 2.5 V, the part can directly digitize ±2.5 V differential signals that map to typical Li-ion cell stack voltages after dividing. The 100 kSPS sample rate can handle cell balancing events in real time for pack currents up to several hundred amps. For high-voltage packs, place a TVS diode such as SMBJ5.0CA at each analog input pin to protect the ADC against motor-back-EMF transients.
Recommended
Remote Sensor Front-End and Test Equipment
Bench-top and field-portable test equipment use the ADS8345NB/1K as a low-cost, multi-input 16-bit ADC front-end for capturing sensor waveforms from bridge-type, RTD-type, or generic ±5 V output sources. With VREF = VCC/2 and bipolar input mode, full ±5 V signals can be acquired directly without external signal conditioning, simplifying the analog input section. The serial interface also enables easy soldering of the part into compact probe-style form factors where mechanical constraints rule out parallel-bus ADCs. The 100 kSPS sample rate supports audio-bandwidth analysis up to ~40 kHz in alias-free mode, making the part ideal for vibration or acoustic emission monitoring. Use the ADS8345NB/1K with a precision 4.096 V external reference for highest accuracy, and tie the unused input channels to mid-rail at the AGND pin for stable no-noise baseline readings.
Recommended
Recommended Products Summary
Engineering reference data for ADS8345NB/1K — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS8345NB | ADS8345NB/1KG4 | ADS8344N | ADS8343EB/2K5G4 | ADS8344NB/1K |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Resolution | 16 bits | 16 bits | 16 bits | 16 bits | 16 bits | 16 bits |
| Number of Channels | 8 SE / 4 Diff | 8 SE / 4 Diff | 8 SE / 4 Diff | 8 SE / 4 Diff | 4 SE / 2 Diff | 8 SE / 4 Diff |
| Max Sample Rate | 100 kSPS | 100 kSPS | 100 kSPS | 50 kSPS | 100 kSPS | 50 kSPS |
| Hardware Shutdown Pin | Yes (SHDN) | Yes (SHDN) | Yes (SHDN) | No | Yes (SHDN) | No |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Supply Voltage | 2.7–5.25 V (AVDD) | 2.7–5.25 V | 2.7–5.25 V | 2.7–5.25 V | 2.7–5.25 V | 2.7–5.25 V |
Key Differentiators
- Integrated 8-channel analog multiplexer with both single-ended and fully differential modes (vs ADS8343EB/2K5G4)
- Hardware SHDN pin drops quiescent current below 1 µA (vs ADS8344N / ADS8344NB/1K)
- 100 kSPS max throughput vs 50 kSPS for legacy ADS8344 (vs ADS8344N / ADS8344NB/1K)
Design Notes
Decouple both AVDD (analog) and DVDD (digital) supply pins individually as close to the IC as possible, using a 10 µF tantalum or X7R ceramic + 0.1 µF MLCC combination on each rail. The TI datasheet recommends tying AVDD to a low-noise LDO such as TPS7A4701 rather than the 3.3 V switching node, because ripple from upstream converters shows up directly as ADC noise on the analog inputs. Place the LDO physically close to the AVDD pin to keep the analog power-rail impedance low at the AVDD-clock ripple frequency.
The VREF pin requires a low-impedance reference bypass of 10 µF (polarized tantalum) + 0.1 µF (MLCC) placed within 5 mm of the pin; without this network, the AC reference impedance rises and degrades AC accuracy at full 100 kSPS throughput. Use a 4-layer board with a dedicated ground plane split between analog and digital sides, joined at a single point under the ADC's AGND pin. Route the SCLK, DIN, DOUT, CS, BUSY, and CONVST digital signals in a tight bundle near the digital connector and away from the IN0–IN7 analog traces to minimize capacitive coupling.
When operating the serial SPI bus at full 2.5–4.5 MHz SCLK at 100 kSPS, the clock edges couple a few mV of noise into the analog input traces. To preserve the 85 dB SINAD figure, add 50 µA source-resistor isolation (e.g., 100 Ω–1 kΩ) in series with each analog input pin, and avoid running long parallel traces between IN0–IN7 and the SPI bus. If the application allows, lower SCLK to the minimum frequency that maintains the requested throughput; the ADS8345 supports lower SCLK at lower throughput without reconfiguration.
Estimate: at VIN=5 V, VREF=2.5 V, and 100 kSPS continuous conversion, the ADS8345NB/1K's power dissipation is approximately 30–40 mW (8 mW typical at 100 kSPS / +5 V plus digital I/O losses), which is too low for thermal concerns but tight enough that eliminating the SHDN between scans can extend battery life by a factor of 50–100×. Do not connect AVDD directly to a noisy upstream switching regulator; high-frequency ripple > 20 mV pk-pk at the AVDD pin couples directly through the modulator and destroys the 85 dB SINAD. Avoid placing the analog input traces near the SCLK trace running on an adjacent layer for the first 10 mm of the IC — the capacitive coupling can sneak 10–30 mV of clock feedthrough into the analog input path.
Compliance Information
RoHS and REACH compliance per Texas Instruments ADS8345 product page. /NB suffix denotes Lead-Free finish. Halogen-free status not explicitly confirmed in the verified web data; AEC-Q100 not qualified - choose automotive-grade ADC for vehicular applications. Not classified as EU hazardous substance per current SVHC list (no SVHC threshold exceeded as of 2026-10-13).
