MAX147AEAP+TG068 - 12-Bit 8-Ch Serial ADC | Maxim Integrated
MPN: MAX147AEAP+TG068 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.4 | $164.00 |
| 100 | $13.2 | $1,320.00 |
| 500 | $10.8 | $5,400.00 |
| 1,000 | $8.95 | $8,950.00 |
MAX147AEAP+TG068 Overview
A successive-approximation-register (SAR) ADC is a type of data converter that uses a binary search algorithm against an internal DAC to digitize an analog input in N clock cycles, where N is the resolution in bits. The SAR architecture is valued for its deterministic latency, lack of pipeline delay, and excellent DC accuracy, making it well-suited for multiplexed data-acquisition systems, industrial process control, and instrumentation front-ends. Within the broader semiconductor taxonomy, the MAX147 belongs to the data converter family, which sits inside the signal-chain block of analog mixed-signal ICs.
Key features of the MAX147 include a single +2.7 V to +3.6 V supply operation (MAX147 variant), an internal 2.5 V reference with the option to use an external reference, software-configurable unipolar/bipolar input ranges, and a hardware-/software-controlled shutdown mode that drops supply current to below 10 uA. The integrated 8-to-1 input multiplexer allows a single ADC core to digitize up to eight analog signals in sequence, reducing both BOM cost and PCB area compared with per-channel ADC solutions.
From an architectural depth, the MAX147 employs a charge-redistribution DAC with a precision laser-trimmed reference and an input track/hold bandwidth exceeding the Nyquist requirement for 133 ksps operation. The serial interface shifts out conversion results MSB-first, supporting both SPI-mode-0 and MODE-1 timing for direct connection to most microcontroller SPI peripherals without glue logic.
Typical applications include portable data loggers, battery-powered instrumentation, pen digitizers, and isolated industrial sensor front-ends. Designers choose the MAX147 when they need a small-pin-count, multiplexed ADC that can wake from a sub-10 uA shutdown to perform periodic scans and return to sleep between conversions.
Drop-in alternatives for MAX147AEAP+TG068 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX147AEAP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX147BCAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX146AEAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX147BCAP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX147BEAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX146BEAP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX147AEAP+TG068 Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Number of Input Channels | 8 single-ended / 4 differential |
| Input Multiplexer | 8-to-1 (single-ended) or 4-to-1 (differential) |
| Sampling Rate | 133 ksps (max) |
| ADC Architecture | SAR (Successive Approximation) |
| Supply Voltage (Analog/Digital) | +2.7 V to +3.6 V (single supply) |
| Supply Current (full speed) | 1.5 mA (typical at 133 ksps) |
| Shutdown Current | < 10 uA |
| Internal Reference | 2.5 V |
| External Reference Support | Yes |
| Serial Interface | SPI / QSPI / MICROWIRE-compatible |
| Interface Logic Levels | CMOS, VDD-referenced |
| Operating Temperature Range | -40 C to +85 C (E temperature grade) |
| Package | 20-pin SSOP |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Orderable Suffix | +TG068 (customer-specific tape-and-reel) |
MAX147AEAP+TG068 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 — Reference voltage input/output (internal 2.5 V) |
| Pin 11 | SHDN — Shutdown control (active low) |
| Pin 12 | CS — Chip select (active low) |
| Pin 13 | DIN — Serial data input |
| Pin 14 | SCLK — Serial clock input |
| Pin 15 | DOUT — Serial data output |
| Pin 16 | DGND — Digital ground |
| Pin 17 | VDD — +2.7 V to +3.6 V supply |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
MAX147AEAP+TG068 is suitable for 6 applications: Portable Battery-Powered Data Logger, Industrial Process Control Sensor Front-End, Pen Digitizer / Tablet Input Front-End, Battery-Powered Medical Monitoring (battery-powered health monitoring), Isolated Industrial Sensor Module, Handheld Test & Measurement Instrumentation.
Portable Battery-Powered Data Logger
The MAX147AEAP+TG068 is well-suited for portable multi-channel data loggers that need to digitize slow-moving analog signals (temperature, voltage, current) on a duty-cycled schedule. Its 8-to-1 input multiplexer lets one ADC core scan up to eight sensors without extra signal-chain ICs, while its < 10 uA shutdown current between scans keeps average battery drain low. At a 133 ksps maximum sample rate it oversamples most thermocouple and battery-monitoring channels, and its SPI-compatible serial interface attaches directly to low-power microcontrollers such as the MAX32620 or similar ARM Cortex-M parts. Trade-off: SAR architecture means the input track/hold requires sufficient source impedance headroom; add an input buffer if your sensor impedance exceeds 1 kohm.
Recommended
Industrial Process Control Sensor Front-End
In industrial process-control front-ends the MAX147AEAP+TG068 digitizes 4-20 mA loop signals, RTD/thermocouple amplifier rails, and bridge-excitation outputs through its 8-channel MUX. Its SAR architecture gives deterministic per-sample latency, which simplifies synchronized control loops that must react within one conversion cycle. The 12-bit resolution is adequate for sensor readout at the panel-meter accuracy level, and the -40 C to +85 C industrial temperature range covers most factory-floor environments. Add an external 4.096 V reference if your application needs the full-scale range to align with 4-20 mA scaling; the internal 2.5 V reference leaves headroom for sensor offsets below ground.
Recommended
Pen Digitizer / Tablet Input Front-End
The MAX147AEAP+TG068 is a classic choice for pen-digitizer and graphics-tablet input front-ends that scan an array of analog sense lines from the digitizer surface. Its 8-to-1 MUX and 133 ksps throughput enable rapid sequential scanning of multiple pen-position axes and pressure sensors, while the 3 V single-supply operation matches battery-powered tablet designs. The SPI/QSPI/MICROWIRE-compatible serial interface can stream conversion results to a host MCU without additional glue logic. Note that for high-speed digitizer sampling you may want to operate the part at its maximum clock; verify your MCU SPI peripheral can sustain the throughput.
Recommended
Battery-Powered Medical Monitoring (battery-powered health monitoring)
The MAX147AEAP+TG068 fits portable health-monitoring devices such as pulse-oximeter front-ends, single-channel ECG patches, and ambulatory patient monitors that digitize low-frequency biopotential signals. Its low 1.5 mA active current and < 10 uA shutdown current extend battery life, while its 12-bit resolution is adequate for heart-rate and SpO2 trending applications. The 8-channel MUX lets one ADC core monitor multiple biopotential electrodes sequentially, reducing BOM. For higher-resolution ECG with full diagnostic bandwidth, pair with an external low-noise instrumentation amplifier in front of the AIN pin.
Recommended
Isolated Industrial Sensor Module
In isolated sensor modules the MAX147AEAP+TG068 sits on the field side of a digital isolator and digitizes analog sensor signals before they cross the isolation barrier, keeping the isolation channel digital-only and reducing common-mode noise pickup. Its 8-channel MUX covers typical multi-sensor junction-box wiring, and its 12-bit SAR conversion provides deterministic latency for closed-loop control. The single +3 V supply aligns with isolated-side DC/DC converters such as the MAX256 or similar driver-plus-transformer solutions. For higher channel counts or higher sampling rates, swap to MAX1296AEEG (different package - not a drop-in).
Recommended
Handheld Test & Measurement Instrumentation
Handheld DMMs, bench multimeters, and portable oscilloscope front-ends use the MAX147AEAP+TG068 to digitize multiple analog measurement channels (voltage, current, temperature) through its integrated 8-channel multiplexer. The SAR architecture gives one-shot conversion with no pipeline delay, which is essential for trigger-armed single-shot measurements in DMMs. The 133 ksps sample rate covers most multimeter-bandwidth requirements, and the SPI interface connects directly to a display-controller MCU. The 20-pin SSOP package is well-suited to small handheld form factors and OLE sensitivity to PCB area.
Recommended
Recommended Products Summary
Engineering reference data for MAX147AEAP+TG068 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX147AEAP+T | MAX147BCAP+ | MAX146AEAP+ | MAX147BCAP+T | MAX147BEAP+ | MAX146BEAP+ |
|---|---|---|---|---|---|---|---|
| Package | SSOP-20 | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Supply Voltage | +2.7 V to +3.6 V | +2.7 V to +3.6 V | +2.7 V to +3.6 V | +4.5 V to +5.5 V | +2.7 V to +3.6 V | +2.7 V to +3.6 V | +4.5 V to +5.5 V |
| Linearity Grade | A-grade (highest) | A-grade | B-grade (lower INL/DNL) | A-grade | B-grade | B-grade | B-grade |
| Temperature Grade | E (-40 to +85 C) | E (-40 to +85 C) | C (0 to +70 C) | E (-40 to +85 C) | C (0 to +70 C) | E (-40 to +85 C) | E (-40 to +85 C) |
| Sampling Rate | 133 ksps | 133 ksps | 133 ksps | 133 ksps | 133 ksps | 133 ksps | 133 ksps |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 4.096 V | 2.5 V | 2.5 V | 4.096 V |
| Pricing (qty 1, USD) | 18.50 | ~16.20 | ~13.50 | ~17.80 | ~13.00 | ~14.20 | ~16.10 |
Key Differentiators
- Customer-specific tape-and-reel +TG068 suffix (vs MAX147AEAP+T)
- A-grade linearity (highest INL/DNL guaranteed) (vs MAX147BCAP+)
- 3 V single-supply operation vs 5 V variant (vs MAX146AEAP+)
- Industrial -40 to +85 C temperature grade (vs MAX147BCAP+)
Design Notes
Decouple VDD with a 0.1 uF ceramic capacitor placed within 5 mm of the VDD pin and a bulk 4.7 uF or larger tantalum/ceramic capacitor. Add an additional 4.7 uF bypass on the REF pin to keep reference noise below the converter's noise floor; inadequate REF bypassing is the most common source of degraded ENOB in field returns.
Do not exceed the absolute-maximum analog input range of VDD + 0.3 V on any AIN pin; over-voltage on an input channel can permanently damage the MUX. The MAX147 single-supply design cannot digitize signals below ground - for true bipolar input ranges you must add an input signal-conditioning network or choose a bipolar-input ADC like the MAX1274AETC+. Confirmed from the manufacturer datasheet absolute-maximum ratings table.
Drive AIN inputs from low-impedance sources (<= 1 kohm source impedance) to avoid conversion errors caused by incomplete settling of the internal track/hold. If your sensor impedance is higher, add an op-amp buffer (such as a MAX4475) in front of the ADC. Estimate: with 5 kohm source and 13 pF internal sampling capacitor, the 12-bit settling time constant is approximately 3 tau = 2 us, which is shorter than the conversion clock and should not limit throughput, but still adds distortion at low sampling rates if the input mux is switched mid-acquisition.
Route the analog AIN traces and the digital SCLK/DOUT/DIN/CS traces on opposite sides of the SSOP-20 package, with AGND and DGND tied at a single star ground under the IC. Keep the REF trace short and surrounded by ground pour to prevent digital switching noise from coupling into the reference - this is the single biggest contributor to degraded THD in SAR ADC layouts. Do not run digital traces directly under the analog pins or the exposed paddle area.
Compliance Information
RoHS and lead-free status confirmed from Maxim Integrated product page (now under Analog Devices). Halogen-free status not explicitly stated in the available data. Not AEC-Q100 qualified - choose a Q1/AEC-Q100 part for automotive applications.
