ADS8406IPFBTG4 - 16-Bit 1.25MSPS SAR ADC | Texas Instruments
MPN: ADS8406IPFBTG4 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $23.26 | $23.26 |
| 10 | $21.45 | $214.50 |
| 100 | $18.9 | $1,890.00 |
| 500 | $16.5 | $8,250.00 |
| 1,000 | $14.2 | $14,200.00 |
ADS8406IPFBTG4 Overview
An SAR ADC is a type of analog-to-digital converter that performs a binary search across an internal capacitive DAC in N clock cycles, producing one conversion per cycle with no pipeline latency. Compared with delta-sigma or pipelined ADCs, SAR converters are valued for deterministic latency, low power, and excellent behavior on multiplexed or single-shot inputs, making them a workhorse in industrial instrumentation. The ADS8406 belongs to TI's broad precision-SAR family, sitting between low-speed 16-bit audio ADCs and high-speed 14/16-bit pipeline parts.
Key features include 16-bit resolution with no missing codes, a 1.25 MHz maximum sample rate, a fully differential pseudo-bipolar input supporting ±2*VREF or 0-4*VREF ranges, a low conversion time around 650 ns, and an internal 4.096 V reference that simplifies BOM. The 48-TQFP package exposes a standard parallel interface that can be configured as a single 16-bit read or two 8-bit cycles, easing connection to 8-bit microcontrollers and DSPs. Typical INL is around +/-2 LSB and SINAD exceeds 85 dB at lower input frequencies.
Typical applications include industrial process control and PLC analog input modules, optical-module bias control, multi-channel data-acquisition front ends, medical instrumentation such as patient monitoring, and precision weigh scales or strain-gauge signal chains. The combination of a 1.25 MSPS throughput and low 35 mW typical dissipation lets the part serve both multiplexed and continuous-stream designs.
When designing with the ADS8406, use a low-impedance RC network at the analog input and decouple AVDD/DRVDD with 1 uF and 100 nF ceramic capacitors placed within 5 mm of the supply pins. Keep the parallel bus short and series-terminate at the driver to avoid digital coupling into the analog input. The internal 4.096 V reference can be bypassed for an external reference if higher accuracy is required.
This page synthesizes distributor pricing, drop-in alternatives from the ADS840x and ADS841x family, and practical design notes not collected in the TI datasheet alone.
Drop-in alternatives for ADS8406IPFBTG4 — 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 ADS8406IPFBTG4 (same form factor and footprint) — differing in Conversion Time, Operating Temperature Range, Package, Architecture, Input Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADS8406IPFBRG4
✅ Drop-In✓ In Stock
$11.92 / Unit
View Datasheet →ADS8406IBPFBTG4
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8406IPFBRG4
✅ Drop-In✓ In Stock
$11.92 / Unit
View Datasheet →ADS8406IBPFBR
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8406IPFBT
✅ Drop-In📋 Reference alternative (not in catalog)
ADS8401IPFBRG4
✅ Drop-In✓ In Stock
$11.75 / Unit
View Datasheet →ADS8406IPFBTG4 Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Sample Rate | 1.25 MSPS |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 |
| Input Type | Pseudo-Bipolar, Fully Differential |
| Internal Reference Voltage | 4.096 V |
| Data Interface | Parallel (16-bit or 8-bit bus) |
| Conversion Time | 650 ns (typ) |
| Analog Supply Voltage | 5 V |
| Digital Supply Voltage | 3 V or 5 V |
| Power Dissipation (typ) | 35 mW |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Package | 48-TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
ADS8406IPFBTG4 Pin Configuration
| Pin 1 | AVDD — Analog supply, 5V |
| Pin 2 | INP — Positive analog input |
| Pin 3 | INN — Negative analog input |
| Pin 4 | AGND — Analog ground |
| Pin 5 | REF — Reference I/O |
| Pin 6 | REFCAP — Reference bypass capacitor |
| Pin 7 | BYPAS — Internal bias bypass |
| Pin 8 | AGND — Analog ground |
| Pin 9 | AVDD — Analog supply, 5V |
| Pin 10 | CS — Chip select, active low |
| Pin 11 | RD — Read input, active low |
| Pin 12 | BUSY — Conversion in progress, active high |
| Pin 13 | DRVDD — Digital I/O supply |
| Pin 14 | DRGND — Digital ground |
| Pin 15 | CONVST — Conversion start input |
| Pin 16 | RANGE — Input range select |
| Pin 17 | BYTE — Byte/parallel mode select |
| Pin 18 | RESET — Reset input |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | D0 — Data bit 0 (LSB) |
| Pin 21 | D1 — Data bit 1 |
| Pin 22 | D2 — Data bit 2 |
| Pin 23 | D3 — Data bit 3 |
| Pin 24 | D4 — Data bit 4 |
| Pin 25 | D5 — Data bit 5 |
| Pin 26 | D6 — Data bit 6 |
| Pin 27 | D7 — Data bit 7 |
| Pin 28 | D8 — Data bit 8 |
| Pin 29 | D9 — Data bit 9 |
| Pin 30 | D10 — Data bit 10 |
| Pin 31 | D11 — Data bit 11 |
| Pin 32 | D12 — Data bit 12 |
| Pin 33 | D13 — Data bit 13 |
| Pin 34 | D14 — Data bit 14 |
| Pin 35 | D15 — Data bit 15 (MSB) |
| Pin 36 | DRGND — Digital ground |
| Pin 37 | DRVDD — Digital I/O supply |
| Pin 38 | TAG — Tag input for output bit |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | AGND — Analog ground |
| Pin 42 | REFGND — Reference ground |
| Pin 43 | REF — Reference I/O |
| Pin 44 | AGND — Analog ground |
| Pin 45 | AVDD — Analog supply, 5V |
| Pin 46 | AVDD — Analog supply, 5V |
| Pin 47 | AGND — Analog ground |
| Pin 48 | NC — Not connected (per datasheet) |
Typical Applications
ADS8406IPFBTG4 is suitable for 6 applications: Industrial Process Control / PLC Analog Input, Precision Weigh Scales and Strain-Gauge Signal Chains, Optical Module Bias Control, Multi-Channel Data Acquisition Front End, Medical Patient Monitoring, Test and Measurement Instrumentation.
Industrial Process Control / PLC Analog Input
The ADS8406's 1.25 MSPS throughput and 16-bit no-missing-codes resolution make it well matched to PLC analog input modules that scan multiple sensors rapidly. Its fully differential pseudo-bipolar input rejects common-mode noise from long field wiring, while the internal 4.096 V reference removes the need for an external precision reference in cost-sensitive designs. Place 1 uF and 100 nF ceramic bypass capacitors on AVDD within 5 mm of the pins, and use a 20 ohm RC at the analog input to limit charge-kickback. The parallel interface simplifies connection to industrial Cortex-M or DSP controllers that lack high-speed serial ports, while 35 mW typical dissipation enables 8-channel multiplexed front ends without exceeding thermal budgets.
Recommended
Precision Weigh Scales and Strain-Gauge Signal Chains
Weigh scales require 16-bit or higher resolution to capture sub-gram load cell changes, and the ADS8406 delivers true 16-bit performance with the 4.096 V internal reference simplifying ratiometric measurement of a bridge excited near 4.096 V. Its low integral non-linearity directly translates to a wide dynamic range that supports both small and large loads on the same load cell. The differential input rejects thermocouple and power-line noise picked up by long cables, and the 35 mW dissipation keeps the analog front end thermally quiet, which is critical for strain-gauge stability. Use a low-noise op-amp such as the OPA227 as an input buffer to maintain full-scale accuracy across the operating temperature range.
Recommended
Optical Module Bias Control
Optical transceivers and LiDAR receivers need closed-loop control of laser bias and modulation currents, where a fast and accurate ADC is required to digitize monitor photodiode currents. The 1.25 MSPS speed of the ADS8406 easily tracks a 10 kHz control loop while leaving margin for housekeeping channels. The pseudo-bipolar differential input directly digitizes photodiode currents biased near mid-rail, eliminating the need for a transimpedance front end with bipolar supplies. The internal 4.096 V reference is stable enough for set-and-forget bias calibration, and the parallel interface can be shared with an FPGA host that handles modulation and clocking in a single chip.
Recommended
Multi-Channel Data Acquisition Front End
Multi-channel DAQ systems for vibration, seismic, or sonar front-end digitizers benefit from the deterministic single-cycle latency of the ADS8406. The 1.25 MSPS throughput per channel allows 8 channels to be time-multiplexed at 156 kSPS per channel with full 16-bit accuracy, and the low aperture delay makes channel-to-channel phase matching trivial. The 48-TQFP footprint keeps board area small, leaving room for a per-channel input multiplexer and antialias filter. Driving the parallel bus directly into an FPGA FIFO enables continuous streaming to memory with zero host-CPU overhead, ideal for capturing transient events in the field.
Recommended
Medical Patient Monitoring
Patient monitors for ECG, SpO2, and invasive blood pressure all require 16-bit analog front ends to capture small biopotential signals below 1 mV with sufficient dynamic range. The ADS8406's differential input rejects 50/60 Hz mains pickup from long patient leads when paired with a right-leg drive circuit, and the internal 4.096 V reference simplifies IEC 60601-1 calibration. The 35 mW dissipation keeps the analog section cool, important when the monitor is worn on the body or used near sensitive skin electrodes. The parallel interface connects to a Cortex-M4 host that runs the display and the safety-critical alarm algorithms in a single chip.
Recommended
Test and Measurement Instrumentation
Bench-top oscilloscopes, power analyzers, and arbitrary waveform generators all use 16-bit ADCs to characterize analog signals. The 1.25 MSPS throughput of the ADS8406 covers audio-band and slow-RF test signals comfortably, while its 16-bit resolution enables better than 0.005% full-scale measurement accuracy. The pseudo-bipolar input directly digitizes signals swinging around ground without the extra level-shift circuit required by single-supply ADCs, and the parallel data bus can be captured directly by an FPGA or a high-speed DSP for FFT and THD analysis. The 48-TQFP package also has good thermal dissipation for the long acquisition sessions typical in automated test.
Recommended
Recommended Products Summary
Engineering reference data for ADS8406IPFBTG4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS8406IPFBRG4 | ADS8406IBPFBTG4 | ADS8406IPFBR | ADS8401IPFBRG4 |
|---|---|---|---|---|---|
| Package | 48-TQFP (7x7) | 48-TQFP (7x7) | 48-TQFP (7x7) | 48-TQFP (7x7) | 48-TQFP (7x7) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 12 bit |
| Sample Rate | 1.25 MSPS | 1.25 MSPS | 1.25 MSPS | 1.25 MSPS | 1.25 MSPS |
| Architecture | SAR | SAR | SAR | SAR | SAR |
| Input Type | Pseudo-Bipolar, Fully Differential | Pseudo-Bipolar, Fully Differential | Pseudo-Bipolar, Fully Differential | Pseudo-Bipolar, Fully Differential | Pseudo-Bipolar, Fully Differential |
| Internal Reference | 4.096 V | 4.096 V | 4.096 V | 4.096 V | 4.096 V |
| Data Interface | Parallel (16/8-bit) | Parallel (16/8-bit) | Parallel (16/8-bit) | Parallel (16/8-bit) | Parallel (16/8-bit) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Higher resolution than 12-bit predecessors in same package (vs ADS8401IPFBRG4)
- Industrial-screen variant for harsh environments (vs ADS8406IPFBRG4)
- Internal 4.096 V reference eliminates external reference BOM (vs ADS8383IPFBTG4)
Design Notes
Decouple AVDD and DRVDD with 1 uF and 100 nF ceramic capacitors placed within 5 mm of the supply pins. The ADS8406 draws roughly 35 mW typical at 1.25 MSPS from a 5 V analog supply; use a star-ground topology to keep digital return currents from polluting the analog ground. Estimated: total quiescent current at full speed is approximately 7 mA from 5 V AVDD and 1 mA from 3.3 V DRVDD, based on the typical 35 mW analog power figure from the datasheet.
The ADS8406 parallel output bus toggles all 16 data lines plus CS, RD, BUSY and TAG on every conversion, producing high-frequency noise. Series-terminate each output with 20-33 ohm resistors to dampen reflections, and place the bus traces over a continuous ground plane to limit crosstalk. Keep the analog input traces short and symmetric, with a 20 ohm series resistor and a 1 nF-10 nF capacitor at the input pin to form a charge-kickback filter.
Do not operate the ADS8406 without the REFCAP and BYPAS capacitors in place; the internal 4.096 V reference and bias circuits need the external caps to meet linearity spec. Reading the ADC during the BUSY high period yields incorrect data, so gate RD with BUSY or use the falling edge as a hardware interrupt. The RANGE input must be tied to a known logic level, not left floating, or input range selection becomes indeterminate. Estimated: with REFCAP = 10 uF and BYPAS = 1 uF, the reference settles in roughly 10 ms after power-up.
The 48-TQFP package has a theta_JA of approximately 70 C/W on a standard 4-layer JEDEC test board. At 35 mW typical dissipation the self-heating is well under 1 C, so thermal management is not a concern for the standard grade. If you operate the part at maximum sample rate continuously, add 100 mm^2 of top-side copper over the AVDD and AGND pins to keep junction rise below 5 C. Estimated: junction-to-ambient rise is approximately 70 C/W * 0.035 W = 2.45 C with the minimum copper footprint.
Compliance Information
RoHS and REACH compliance per TI product page. The ADS8406IPFBTG4 is Pb-free and supplied on tape and reel. AEC-Q100 not qualified - this is an industrial-grade (-40C to +85C) part, not automotive.
