MAX148AEPP+ - 10-Bit 8-Ch 133ksps 5.25V Precision ADC | Maxim Integrated
MPN: MAX148AEPP+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.42 | $11.42 |
| 10 | $10.28 | $102.80 |
| 100 | $9.07 | $907.00 |
| 500 | $7.92 | $3,960.00 |
| 1,000 | $6.95 | $6,950.00 |
MAX148AEPP+ Overview
What is a SAR ADC? A successive-approximation-register (SAR) analog-to-digital converter is a precision data-conversion architecture that builds the output code bit-by-bit using an internal DAC and comparator. SAR ADCs sit in the broader hierarchy of data converters (ADC) -> mixed-signal ICs -> signal chain ICs -> power management and analog semiconductors. They are favored for medium-speed, medium-resolution applications where deterministic latency, low power, and small package size matter more than the very high sampling rates of pipelined or sigma-delta ADCs.
Key features include ±1 LSB INL and DNL (max) over the industrial -40°C to +85°C range, a hardware SHDN pin plus software-selectable power-down that drops supply current to under 10 µA between conversions, an external serial clock up to 2 MHz (SPI/QSPI/MICROWIRE compatible), and a flexible reference input accepting ratiometric conversions or an external 2.5V/4.096V reference. The internal MUX-S/H-ADC chain provides true 8-channel scanning with sequential or on-demand channel selection, and automatic shutdown at end-of-conversion further reduces system power in battery-driven designs.
The MAX148 uses a charge-redistribution DAC core with an auto-calibrated comparator and a synchronous serial output that streams the conversion result MSB-first. The serial interface supports daisy-chaining multiple devices (CS line selects the active device), allowing multi-channel expansion without consuming additional microcontroller pins. The wide supply range and reference flexibility make it equally at home on a 3.3V logic rail or a 5V analog rail.
Typical applications include portable data logging, 4-20 mA industrial sensor multiplexing, multi-cell battery monitoring, HVAC thermostat analog front ends, panel meters and digital multimeters, and distributed-control / SCADA analog input modules. The combination of 8-channel input mux, SPI interface, and 1.2 mA operating current also suits handheld medical and instrumentation designs where both channel density and battery life are critical.
When designing with this device, choose an external reference (e.g. MAX6125 or REF02) when absolute accuracy is required; for ratiometric ratiometric bridge or thermistor measurements the supply can serve as the reference. Place a 0.1 µF decoupling capacitor directly at VDD and a 10 µF bulk capacitor at the analog supply pin to suppress digital switching noise that would otherwise couple into the SAR comparator.
This page synthesizes distributor pricing (Mouser/DigiKey), cross-reference alternatives from the Maxim MAX148 family, and PCB-level design guidance that goes beyond the manufacturer datasheet, helping engineers evaluate a drop-in upgrade path quickly.
Drop-in alternatives for MAX148AEPP+ — 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 MAX148AEPP+ (same form factor and footprint) — differing in Mounting Type, Resolution, RoHS Status, Data Interface, Input Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX148BEPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX148BCPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX147AEAP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.88 / Unit
View Datasheet →MAX148AEPP+ Maximum Ratings & Electrical Characteristics
| Resolution | 10 bit |
| Number of Channels | 8 single-ended / 4 differential |
| Sampling Rate | 133 ksps |
| Supply Voltage | +2.7 V to +5.25 V |
| Supply Current (Active) | 1.2 mA typ at 133 ksps |
| Supply Current (Shutdown) | < 10 µA |
| INL (max) | ±1 LSB |
| DNL (max) | ±1 LSB |
| Input Type | Differential, Single-Ended |
| Data Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Architecture | SAR (Successive Approximation) |
| Configuration | MUX-S/H-ADC |
| Ratio S/H:ADC | 1:1 |
| Number of ADCs | 1 |
| Reference Type | External (ratiometric or fixed) |
| Shutdown Pin | Yes (active-low SHDN) |
| Operating Temperature | -40 °C to +85 °C (industrial) |
| Package | 20-pin PDIP (DIP-20) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
MAX148AEPP+ Pin Configuration
| Pin 1 | AIN0 — Analog input channel 0 |
| Pin 2 | AIN1 — Analog input channel 1 |
| Pin 3 | AIN2 — Analog input channel 2 |
| Pin 4 | AIN3 — Analog input channel 3 |
| Pin 5 | AIN4 — Analog input channel 4 |
| Pin 6 | AIN5 — Analog input channel 5 |
| Pin 7 | AIN6 — Analog input channel 6 |
| Pin 8 | AIN7 — Analog input channel 7 |
| Pin 9 | AGND — Analog ground |
| Pin 10 | REF — External reference input |
| Pin 11 | VDD — Analog +5V supply |
| Pin 12 | SHDN — Active-low shutdown pin |
| Pin 13 | SSTRB — Serial strobe output |
| Pin 14 | DOUT — Serial data output |
| Pin 15 | SCLK — Serial clock input |
| Pin 16 | CS — Active-low chip select |
| Pin 17 | DGND — Digital ground |
| Pin 18 | CHSEL — Channel select / serial configuration input |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
MAX148AEPP+ is suitable for 6 applications: Portable Multi-Sensor Data Logging, 4-20 mA Industrial Sensor Multiplexing, Multi-Cell Battery Monitoring, HVAC Thermostat Analog Front End, Digital Panel Meter and Multimeter, Distributed Control / SCADA Analog Input Modules.
Portable Multi-Sensor Data Logging
The MAX148AEPP+ integrates an 8-channel analog multiplexer, 10-bit SAR ADC, and SPI interface in a single 20-pin PDIP, making it a one-chip front end for handheld data loggers. At 1.2 mA active current and under 10 µA in shutdown, the part is ideal for Li-ion or coin-cell powered recorders where multiple analog signals (temperature, pressure, flow, voltage) must be sampled at 133 ksps aggregate. Place 0.1 µF + 10 µF decoupling at VDD, use an external MAX6125 reference for absolute accuracy, and use the active-low SHDN pin to put the device to sleep between scan bursts. This avoids needing an external mux and keeps BOM count low.
Recommended
4-20 mA Industrial Sensor Multiplexing
For PLCs and distributed-control analog input modules, the MAX148AEPP+ delivers 8 single-ended or 4 differential inputs through its internal mux, eliminating an external analog switch and reducing board area. The ±1 LSB INL/DNL over -40°C to +85°C is suitable for 4-20 mA loop monitoring when paired with burden resistors and input protection. The wide 2.7V-5.25V supply supports both 3.3V logic and legacy 5V analog rails, and the SPI/QSPI/MICROWIRE-compatible interface daisy-chains multiple MAX148 devices for 16/24-channel expansion. Use TVS protection on each AIN pin and a low-pass RC filter before each input.
Recommended
Multi-Cell Battery Monitoring
The 8-channel mux of the MAX148AEPP+ directly monitors up to 8 Li-ion or NiMH cells (or 4 differential pairs) in a battery management system, with 10-bit resolution adequate for state-of-charge estimation when cell balancing is in place. The 2.7V-5.25V supply range allows operation from a single cell or stack voltage, and the <10 µA shutdown current prevents quiescent drain when the pack is idle. The SPI interface streams conversion results to a host microcontroller for coulomb counting. Add per-channel RC filters and Zener clamps to handle inductive transients during cell balancing.
Recommended
HVAC Thermostat Analog Front End
Smart thermostats require multiple analog inputs (temperature, humidity, setpoint potentiometer, supply monitor) that the MAX148AEPP+ can scan sequentially through its 8-channel mux. Its 133 ksps throughput supports oversampling for noise reduction on temperature channels, and the SPI output integrates directly with low-power thermostat MCUs. The 1.2 mA active current is acceptable in line-powered thermostats, and the shutdown mode keeps idle consumption negligible when the HVAC relay is off. Reference the ADC to the supply for ratiometric measurements of potentiometer or thermistor dividers.
Recommended
Digital Panel Meter and Multimeter
Handheld and benchtop digital multimeters benefit from the 4 differential input pairs of the MAX148AEPP+, supporting voltage, current (via shunt), resistance (via ratiometric measurement), and diode-drop measurements from a single ADC. The 10-bit resolution gives ~10 mV LSB at 5V full-scale, adequate for general-purpose panel meters, and the SPI output simplifies isolation barrier implementation in bench instruments. The industrial -40°C to +85°C range ensures accuracy across wide ambient conditions. Pair with an external 2.5V reference for measurement-grade accuracy.
Recommended
Distributed Control / SCADA Analog Input Modules
In SCADA remote terminal units (RTUs), each MAX148AEPP+ adds 8 analog channels to the system with deterministic SAR latency and a robust SPI interface that operates over isolation barriers. The 133 ksps per-device throughput supports the burst sampling required by event-driven SCADA polling, while the wide supply tolerance handles 24V industrial bus rails via local regulation. Daisy-chain multiple MAX148AEPP+ devices through their shared SPI to scale up to 64+ channels per RTU without additional microcontroller pins. Use the SHDN pin for input-card power cycling during fault events.
Recommended
Recommended Products Summary
Engineering reference data for MAX148AEPP+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX148BEPP+ | MAX148BCPP+ | MAX147AEAP |
|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 20-pin PDIP | 20-pin PDIP - same | 20-pin PDIP - same | 20-pin PDIP - same |
| Resolution | 10 bit | 10 bit | 10 bit | 12 bit |
| Sampling Rate | 133 ksps | 200 ksps | 133 ksps | 133 ksps |
| Number of Channels | 8 single-ended / 4 differential | 8 single-ended / 4 differential | 8 single-ended / 4 differential | 8 single-ended / 4 differential |
| Supply Voltage | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V |
| INL (max) | ±1 LSB | ±1 LSB | ±1 LSB | ±1 LSB |
| Data Interface | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Single-package 8-channel analog multiplexer with SAR ADC (vs MAX1162ACUB+)
- Industrial -40 °C to +85 °C operating range with PDIP package (vs MAX148BEPP+)
- Sub-10 µA shutdown current with automatic wakeup on serial access (vs MAX147AEAP)
Design Notes
Place a 0.1 µF ceramic decoupling capacitor within 5 mm of the VDD pin and a 10 µF bulk capacitor (tantalum or ceramic) on the same analog rail. The MAX148AEPP+ SAR core draws brief current spikes during conversion; inadequate decoupling can couple into the reference and degrade ±1 LSB linearity. Keep digital and analog ground returns short and join at a single star point under the IC. Use the active-low SHDN pin (drive HIGH through 100 kΩ) to drop quiescent current below 10 µA between conversion bursts in battery designs.
Route the analog input traces as short as possible and guard them with a ground pour to minimize capacitive coupling from digital lines. Keep the SCLK and DOUT traces away from AIN0-AIN7 - the SAR comparator and reference are sensitive to digital switching noise. For through-hole PDIP prototypes, hand-wire the decoupling caps directly at the VDD pin to avoid socket-induced inductance. When designing the 4-20 mA frontend, place a 100 Ω + 1 nF RC filter at each AIN to suppress RF interference from industrial environments.
Do not exceed the absolute maximum analog input of VDD + 0.3V; use external TVS diodes or clamp diodes to AGND/VDD if the input can be overdriven by fault conditions. The MAX148AEPP+ does not include input ESD protection rated for industrial transients - add series resistors and TVS at the connector. Ensure SCLK does not exceed 2 MHz or the conversion accuracy will degrade. When using the internal multiplexer, leave at least 1 µs settling time after switching channels before initiating a conversion to avoid channel-to-channel crosstalk.
For long cable runs (>300 mm) between the microcontroller and the MAX148AEPP+, add a 100 Ω series resistor at SCLK and DOUT near the driver to damp reflections. Use a 4-wire SPI connection (SCLK, DOUT, CS, GND) to avoid ground bounce; the MAX148AEPP+ has separate AGND and DGND pins (9 and 17) - tie both to a low-impedance ground plane, not to the same trace. The SSTRB output goes high during the internal acquisition phase and is a useful signal to qualify DOUT data on the host side.
Compliance Information
RoHS/REACH compliance and lead-free per Maxim Integrated product declaration. Not AEC-Q100 qualified - this is a commercial/industrial grade part. For automotive applications consult Maxim/Analog Devices automotive-grade alternatives.
