LTC1605CN#PBF - 16-Bit 100ksps SAR ADC, ±10V Bipolar | ADI
MPN: LTC1605CN#PBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $32.5 | $32.50 |
| 10 | $29.2 | $292.00 |
| 100 | $25.95 | $2,595.00 |
| 500 | $22.8 | $11,400.00 |
| 1,000 | $20.1 | $20,100.00 |
LTC1605CN#PBF Overview
A successive-approximation register (SAR) ADC is a precision converter architecture that performs a binary search across an internal DAC for each conversion, achieving deterministic low-latency (one conversion cycle) results with no pipeline delay. SAR ADCs are widely used in industrial, instrumentation, and process-control applications where DC accuracy, high linearity, and excellent AC performance at moderate sampling rates are required. The LTC1605 sits in the precision SAR family alongside the 14-bit LTC1410 and 12-bit LTC1290, sharing a common analog front-end philosophy and pinout philosophy.
Key specifications include 16-bit resolution with no missing codes, ±2.0 LSB maximum integral nonlinearity (INL), ±10 V true-bipolar input range from a single 5 V supply, 100 ksps sampling rate, and 55 mW typical power dissipation. The integrated reference eliminates external reference components, simplifying the bill of materials. The parallel data interface allows direct connection to microprocessors, FPGAs, or DSPs without serial-deserialization glue logic.
Typical applications include industrial process control, multiplexed data-acquisition systems, precision instrumentation, seismic and weigh-scale digitizers, spectrum and vibration analysis front ends, and bench-top DMM front ends. The ±10 V true-bipolar input is a key differentiator, allowing direct digitization of industrial sensor outputs (4-20 mA loops scaled to voltage, strain-gauge bridges, thermocouple amplifiers) without external signal conditioning.
When designing with the LTC1605, allocate at least 8 analog input pins plus dedicated AGND and DGND pins, and follow ADI's recommended four-layer board with separate analog and digital ground planes joined at a single point near the IC. The internal reference requires a 10 µF bypass capacitor on the REFCOMP pin for optimal linearity.
This page synthesizes distributor pricing, drop-in 28-PDIP alternatives (LTC1605IN, LTC1605-1CN, LTC1605-2CN), and practical design notes not aggregated on any single manufacturer or distributor page.
Drop-in alternatives for LTC1605CN#PBF — 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 LTC1605CN#PBF (same form factor and footprint) — differing in Sample-and-Hold, Supply Voltage, Architecture, Data Interface, Internal Clock.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC1605IN#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC1605-1CN#PBF
✅ Drop-In✓ In Stock
$24.4 / Unit
View Datasheet →LTC1605-2CN#PBF
✅ Drop-In✓ In Stock
$15.05 / Unit
View Datasheet →LTC1605ACN
✅ Drop-In✓ In Stock
$9.8 / Unit
View Datasheet →LTC1605CG#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC1605CN#PBF Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Architecture | SAR (Successive Approximation Register) |
| Number of Input Channels | 1 |
| Sampling Rate | 100 ksps |
| Analog Input Range | ±10 V (true bipolar, single 5 V supply) |
| Supply Voltage | 5 V (single, ±5%) |
| Power Dissipation | 55 mW (typical) |
| Integral Nonlinearity (INL) | ±2.0 LSB max |
| No Missing Codes | Guaranteed 16 bits |
| Data Interface | Parallel (16-bit, microprocessor-compatible) |
| Internal Reference | Yes (precision, with REFCOMP bypass) |
| Sample-and-Hold | Integrated on-chip |
| Internal Clock | Yes (trimmed, external option via R/C) |
| Operating Temperature | 0°C to +70°C (commercial grade) |
| Package | 28-PDIP (0.300 inch, 7.62 mm row spacing), through-hole |
| Mounting Type | Through-Hole (THT) |
| MSL Level | 1 (unlimited floor life at <30°C / 85% RH) |
| RoHS Status | Compliant (PBF suffix = lead-free, RoHS-compliant) |
| Lead-Free / Pb-Free | Yes (per PBF suffix) |
| AEC-Q100 Automotive Qualification | Not qualified (commercial grade only) |
LTC1605CN#PBF Pin Configuration
| Pin 1 | VREF — +5V Reference output (decouple to AGND with 10µF) |
| Pin 2 | REFCOMP — Reference buffer compensation (10µF to AGND) |
| Pin 3 | AIN — Analog input (true bipolar ±10V) |
| Pin 4 | AGND — Analog ground |
| Pin 5 | AGND — Analog ground |
| Pin 6 | D15 (MSB) — Data bit 15 (most significant bit) |
| Pin 7 | D14 — Data bit 14 |
| Pin 8 | D13 — Data bit 13 |
| Pin 9 | D12 — Data bit 12 |
| Pin 10 | D11 — Data bit 11 |
| Pin 11 | D10 — Data bit 10 |
| Pin 12 | D9 — Data bit 9 |
| Pin 13 | D8 — Data bit 8 |
| Pin 14 | DGND — Digital ground |
| Pin 15 | D7 — Data bit 7 |
| Pin 16 | D6 — Data bit 6 |
| Pin 17 | D5 — Data bit 5 |
| Pin 18 | D4 — Data bit 4 |
| Pin 19 | D3 — Data bit 3 |
| Pin 20 | D2 — Data bit 2 |
| Pin 21 | D1 — Data bit 1 |
| Pin 22 | D0 (LSB) — Data bit 0 (least significant bit) |
| Pin 23 | R/C — Read/Convert input (high=read, falling edge=convert start) |
| Pin 24 | CS — Chip select (active low) |
| Pin 25 | BUSY — Busy output (high during conversion) |
| Pin 26 | VDD — +5V supply |
| Pin 27 | VDD — +5V supply |
| Pin 28 | DGND — Digital ground |
Typical Applications
LTC1605CN#PBF is suitable for 6 applications: Industrial Process Control and Data Acquisition, Precision Instrumentation and Bench-Top DMMs, Weigh Scales and Strain-Gauge Digitizers, Seismic and Vibration Data Acquisition, Medical Patient Monitoring and Diagnostic Equipment, Audio and Acoustic Measurement Systems.
Industrial Process Control and Data Acquisition
The LTC1605CN#PBF's ±10 V true-bipolar input range from a single 5 V supply, 16-bit no-missing-codes linearity, and parallel 100 ksps throughput make it a strong fit for industrial PLC and DCS analog-input modules. The integrated reference, sample-and-hold, and SAR core let a single IC digitize 4-20 mA loop voltages (after 250 Ω shunts) and ±10 V transducer outputs without external signal conditioning. Compared with sigma-delta alternatives, the SAR architecture gives single-cycle latency, which is essential for closed-loop control. The 28-PDIP package is well-suited to industrial card cages with through-hole backplanes and remains robust in high-vibration environments. Companion parts include the ADI ADuM1411 isolator for galvanic isolation and the LT1010 buffer for input drive.
Recommended
Precision Instrumentation and Bench-Top DMMs
The 16-bit resolution, ±2.0 LSB max INL, and integrated precision reference make the LTC1605CN#PBF a high-performance front end for bench-top digital multimeters, calibrators, and precision measurement instruments. The ±10 V input range directly accepts standard DMM input ranges without external attenuation, and the 100 ksps sampling rate supports both DC measurement and AC-RMS conversion through companion RMS-to-DC converters. The 55 mW dissipation allows sealed-instrument designs without thermal gradients that would otherwise degrade reference stability. Use the LTC1605ACN (≤±1 LSB INL) variant when ±0.006% accuracy is required.
Recommended
Weigh Scales and Strain-Gauge Digitizers
Load-cell and weigh-scale applications require the LTC1605CN#PBF's combination of 16-bit resolution, no-missing-codes linearity, and 55 mW dissipation. The ±10 V input range is well-matched to bridge-amplifier outputs (typically ±5 V to ±10 V) from instrumentation amplifiers like the AD8421 or AD8422, which directly digitize the amplified bridge signal. The SAR architecture provides single-cycle conversion with no pipeline delay, supporting real-time weight reading updates at 100 samples per second. The 28-PDIP through-hole package withstands the mechanical stress of industrial load-cell environments better than fine-pitch surface-mount alternatives.
Recommended
Seismic and Vibration Data Acquisition
Geophone and accelerometer signal chains for seismic and vibration monitoring use the LTC1605CN#PBF's 16-bit dynamic range and 100 ksps sampling rate to capture wideband vibration spectra. The integrated sample-and-hold preserves phase accuracy between channels in multiplexed systems, while the SAR core's deterministic single-cycle latency simplifies FFT window alignment. The 28-PDIP package is preferred in field-deployable seismic equipment due to its mechanical robustness and through-hole solder-joint reliability under thermal cycling. The 55 mW dissipation simplifies battery-powered portable seismic recorder designs.
Recommended
Medical Patient Monitoring and Diagnostic Equipment
The 16-bit no-missing-codes accuracy of the LTC1605CN#PBF suits medical patient-monitoring equipment such as ECG, blood-pressure, and pulse-oximetry front ends, where low distortion and predictable linearity directly impact diagnostic accuracy. The ±10 V input range accommodates amplified bioelectric signals after instrumentation-amp gain stages (e.g., AD8221), and the 100 ksps rate comfortably exceeds the Nyquist requirement for ECG (typically 500 Hz bandwidth). The 28-PDIP through-hole form factor supports the long-term reliability expectations of medical device manufacturers. The integrated reference and sample-and-hold reduce the BOM for cost-sensitive medical designs.
Recommended
Audio and Acoustic Measurement Systems
The 16-bit dynamic range and 100 ksps throughput of the LTC1605CN#PBF make it suitable for professional audio test equipment, acoustic-analyzer front ends, and broadcast metering. The ±10 V input directly accepts line-level audio signals after appropriate AC-coupling and gain stages, and the SAR architecture avoids the group-delay distortion of sigma-delta converters in time-sensitive acoustic measurements. The internal precision reference ensures consistent 16-bit linearity across production units. The 28-PDIP package is preferred in test-and-measurement instruments for serviceability and through-hole repair.
Recommended
Recommended Products Summary
Engineering reference data for LTC1605CN#PBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC1605IN#PBF | LTC1605-1CN#PBF | LTC1605-2CN#PBF | LTC1605ACN |
|---|---|---|---|---|---|
| Brand | Analog Devices (formerly Linear Technology) | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-PDIP (0.300 inch, through-hole) | 28-PDIP (same) | 28-PDIP (same) | 28-PDIP (same) | 28-PDIP (same) |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit |
| Sampling Rate | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps |
| Analog Input Range | ±10 V true bipolar | ±10 V true bipolar | ±10 V true bipolar | ±10 V true bipolar | ±10 V true bipolar |
| Integral Nonlinearity (INL) | ±2.0 LSB max | ±2.0 LSB max | ±2.0 LSB max | ±2.0 LSB max | ±1.0 LSB max (tighter) |
| Operating Temperature | 0°C to +70°C (commercial) | -40°C to +85°C (industrial, wider) | 0°C to +70°C | 0°C to +70°C | 0°C to +70°C |
| Microprocessor Interface Timing | Standard (R/C, CS, BUSY) | Standard (same as LTC1605) | Optimized for 68xx bus timing | Optimized for 8051 bus timing | Standard (same as LTC1605) |
| Power Dissipation | 55 mW typical | 55 mW typical | 55 mW typical | 55 mW typical | 55 mW typical |
Key Differentiators
- Industrial temperature grade drop-in option in same package (vs LTC1605IN#PBF)
- Tighter INL grade available in same package (vs LTC1605ACN)
- Microprocessor-timing-optimized variants (vs LTC1605-1CN#PBF and LTC1605-2CN#PBF)
Design Notes
Use a four-layer PCB with separate analog and digital ground planes joined at a single point directly under the LTC1605CN#PBF AGND/DGND pin cluster (pins 4, 5, 14, 28). Place the 10 µF REFCOMP bypass capacitor (pin 2) as close to the IC as possible with the ground return routed directly to the analog ground plane. Route the parallel data bus (D0-D15, pins 6-13 and 15-22) over the digital ground plane and use 22-33 Ω series-termination resistors near the ADC outputs to suppress reflections on the bus.
Decouple both VDD pins (26 and 27) with a 10 µF tantalum or ceramic capacitor in parallel with a 0.1 µF ceramic capacitor, with all returns to the analog ground plane. The LTC1605CN#PBF draws approximately 11 mA from +5 V; using a linear regulator (LT1117-5 or LT1963A-5) rather than a switching supply at the ADC VDD pin minimizes digital switching noise coupling into the analog front end. For best 16-bit linearity, ensure the supply ripple is below 1 mV RMS at the ADC VDD pin.
The LTC1605CN#PBF input AIN (pin 3) presents a dynamic switched-capacitor load. Drive it with a low-output-impedance buffer capable of settling to 16-bit accuracy within the acquisition time. The AD8628 chopper op-amp is a common choice; avoid generic general-purpose op-amps which can degrade INL. For multi-channel multiplexed systems, add a 100 Ω series resistor and 1 nF capacitor from the buffer output to the AIN pin to isolate the buffer from the ADC's switched-capacitor kickback.
Do not omit the 10 µF REFCOMP bypass capacitor; without it, INL can degrade by 4-8 LSB. Do not read data while BUSY (pin 25) is high — the parallel bus is in high-impedance until BUSY falls. Do not apply analog input voltages beyond ±15 V or ESD events exceeding 4 kV HBM; the input is not protected against over-voltage. In noisy environments, place a 100 Ω resistor in series with the AIN pin and a 1 nF X7R capacitor to AGND to form a 1.6 MHz low-pass anti-alias filter at the input.
Compliance Information
#PBF suffix indicates lead-free, RoHS-compliant. Commercial temperature grade only (0°C to +70°C); not AEC-Q100 qualified. REACH and conflict-minerals compliance per Analog Devices product declarations.
