Analog Devices Inc./Maxim Integrated MAX1247AEPE

Overview

MAX1247AEPE from Maxim Integrated is a 12-bit, 4-channel serial analog-to-digital converter (ADC) with integrated track/hold, software-configurable unipolar/bipolar and single-ended/differential inputs, and SPI/QSPI/MICROWIRE-compatible 4-wire serial interface. It operates from a single +2.7V to +5.25V supply, consumes 1.2mA at 133ksps, and supports external reference input. It is used in portable data logging and battery-powered medical instruments.

For engineers reviewing the MAX1247AEPE datasheet, MAX1247AEPE pinout, MAX1247AEPE application, or MAX1247AEPE equivalent, key selection criteria include its 12-bit resolution, 133ksps conversion rate with external clock, ±1 LSB INL (max), QSOP-16 package, and support for both internal reference buffer (disabled by default) and external VREF down to 1.0V.

Technical Context

The MAX1247AEPE uses successive-approximation register (SAR) architecture with an integrated track/hold circuit that acquires input signals in ≤1.5µs. Its analog input multiplexer supports four single-ended or two pseudo-differential channel pairs (CH0/CH1, CH2/CH3), with COM as common-mode reference.

It features dual clock modes: external serial clock (up to 2MHz) drives both data transfer and conversion timing, while internal clock mode enables flexible readout timing independent of SCLK frequency. The SHDN pin provides three-level control-low for full shutdown (1µA), high for internal reference compensation, and floating for external compensation.

Key Specifications

Pinout & Package

MAX1247AEPE is housed in a 16-pin QSOP package (5.3mm × 10.0mm), occupying the same PCB footprint as an 8-pin SOIC - enabling compact layout in space-constrained portable systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with ADS7822U and MAX11131ETE+, the MAX1247AEPE uniquely balances wide supply range (+2.7V to +5.25V), bipolar/differential configurability, ultra-low shutdown current (1µA), and QSOP-16 compatibility - making it optimal for portable, multi-range, battery-sensitive systems requiring design reuse across 3.3V and 5V platforms.

Availability

MAX1247AEPE is available at Aetrix Electronics and suitable for portable data logging, medical instrumentation, and battery-powered test equipment requiring stable component supply and long-term manufacturability.

Supply support for MAX1247AEPE includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, medical, and portable applications.

The MAX1246/MAX1247 product line delivers low-power, software-flexible 12-bit ADCs optimized for battery-operated systems where supply range adaptability, interface simplicity, and minimal external components are critical.

FAQ

What is the maximum sampling rate achievable with MAX1247AEPE?

The MAX1247AEPE achieves a maximum conversion rate of 133ksps when using a 2MHz external serial clock. This rate assumes 15 clock cycles per conversion (12 for SAR decision + 3 for acquisition setup). At lower clock frequencies or in internal clock mode, the effective sampling rate decreases accordingly. The device's 1.5µs acquisition time and 2.25MHz small-signal bandwidth ensure fidelity at this rate for typical sensor and biomedical signals.

Does MAX1247AEPE include an internal voltage reference?

No, the MAX1247AEPE does not include an internal voltage reference. Unlike the MAX1246 variant, the MAX1247AEPE requires an external reference applied to the VREF pin. Its internal reference buffer is disabled by default and must be explicitly enabled only if used with external compensation (via REFADJ). The datasheet specifies VREF input range as 1.0V to VDD+50mV, supporting ratiometric or precision reference configurations.

How is differential input mode configured on MAX1247AEPE?

Differential input mode on MAX1247AEPE is configured via the 8-bit control byte written to DIN: set bit SGL/DIF (bit 2) to '0', then select channel pair using SEL2–SEL0 bits. Valid differential pairs are CH0/CH1 (SEL=001) and CH2/CH3 (SEL=010). In this mode, the device samples the voltage difference between the two inputs, with COM serving as the common-mode reference point. The input structure is pseudo-differential - only the positive input is actively sampled, so the negative input must remain stable within ±0.5 LSB.

What are the power-down current levels for MAX1247AEPE?

The MAX1247AEPE offers two distinct low-power states: fast power-down draws 54µA (typical) and retains register settings, while full power-down draws 1µA (typical) and resets internal logic. Both are activated via the PD1/PD0 bits in the control byte (01 and 00 respectively). Additionally, asserting SHDN low forces full power-down regardless of control byte settings. These modes enable aggressive energy management in intermittent-sampling applications like wireless sensor nodes.

Can MAX1247AEPE interface directly with a TMS320 DSP family processor?

Yes, the MAX1247AEPE can interface directly with TMS320-family digital signal processors using its SSTRB (serial strobe) output. In internal clock mode, SSTRB goes low at conversion start and high at completion, providing hardware-ready signaling. In external clock mode, SSTRB pulses high for one clock period before the MSB appears on DOUT - enabling precise synchronization of DSP DMA reads. No external logic or level shifters are required, as the interface complies with SPI/QSPI timing and voltage specifications compatible with TMS320 McBSP peripherals.