Analog Devices Inc. AD7575KP-REEL

Overview

AD7575KP-REEL from Analog Devices is an 8-bit successive approximation analog-to-digital converter (ADC) with integrated track-and-hold, single +5 V supply operation, 5 µs conversion time, ±1/2 LSB total unadjusted error, and 0 to +70°C temperature range. It digitizes full-scale signals up to 50 kHz (386 mV/µs slew rate) in microprocessor-based data acquisition systems.

For engineers reviewing the AD7575KP-REEL datasheet, AD7575KP-REEL pinout, AD7575KP-REEL application, or AD7575KP-REEL equivalent, key selection criteria include unipolar/bipolar configuration flexibility, internal/external clock options, 100 ns data access time, and compatibility with Z80H, 8085A-2, 6502B, 68B09, and TMS32010 processors.

Technical Context

The AD7575KP-REEL employs a SAR architecture with on-chip track-and-hold that acquires input signals on the third falling edge of CLK after CS and RD assertion. Its LC2MOS process enables low power (15 mW typ) and fast interface timing without external hold capacitors.

It supports two microprocessor interface modes: Slow Memory (WAIT-state driven, BUSY-controlled) and ROM Interface (non-blocking, dual-read sequencing). The TP pin must be hard-wired HIGH for functional operation and is reserved for factory test.

Key Specifications

Pinout & Package

AD7575KP-REEL is housed in a 20-terminal plastic leaded chip carrier (PLCC, package code P-20A), with gull-wing leads and pin 1 identifier notch. The package is RoHS-compliant and suitable for surface-mount reflow assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit ADC applications.

Compared with AD7575KP-REEL, AD7575KN offers identical electrical performance in a through-hole package, while MAX1112CPE+ trades track-and-hold capability and speed for integrated reference convenience-neither is pin-compatible, and both require layout changes and interface logic review.

Availability

AD7575KP-REEL is available at Aetrix Electronics and suitable for industrial data acquisition, audio digitization, motor control feedback, and portable medical instrumentation requiring stable component supply across extended production lifecycles.

Supply support for AD7575KP-REEL 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7575KP-REEL belongs to Analog Devices' legacy precision ADC product line, designed specifically for cost-sensitive, microprocessor-coupled data acquisition where speed, simplicity, and single-supply operation are critical.

FAQ

What is the maximum analog input frequency supported by the AD7575KP-REEL without accuracy loss?

The AD7575KP-REEL supports full-accuracy digitization of analog inputs up to 50 kHz, corresponding to a 386 mV/µs slew rate for a 2.46 V_PP sine wave. This is enabled by its integrated track-and-hold circuit. Beyond 50 kHz, slew-induced errors increase, and SNR degrades below the specified 45 dB minimum. For higher-frequency signals, external sample-and-hold or faster ADCs are required. The AD7575KP-REEL's specification sheet confirms this limit under "Full Power Signal Bandwidth" and Figure 11 (SNR vs. Input Frequency).

Can the AD7575KP-REEL operate in bipolar mode, and what external components are required?

Yes, the AD7575KP-REEL supports bipolar operation (±5 V input range) using the external resistor network shown in Figure 17 of its datasheet. This requires precision resistors (R2–R8, 0.1% tolerance), an op amp (e.g., TLC271), and proper biasing of AIN to maintain 0–2.46 V compliance at the ADC pin. The output is offset binary. Bipolar mode increases system complexity and component count versus unipolar use, and calibration of offset and full-scale is recommended. The AD7575KP-REEL itself does not contain internal bipolar circuitry.

Is the TP pin on the AD7575KP-REEL functional in normal operation?

No, the TP (Test Pin) on the AD7575KP-REEL is reserved exclusively for factory testing and must be hard-wired to a logic HIGH level (e.g., +5 V via 10 kΩ pull-up) in all application circuits. It has no user-accessible function, cannot be used as an I/O or feedthrough, and leaving it floating or driving it low may cause undefined behavior. This requirement is explicitly stated in the "Timing and Control" section and Figure 12 of the AD7575KP-REEL datasheet.

What clock source options does the AD7575KP-REEL support, and which is recommended for timing-critical applications?

The AD7575KP-REEL supports both internal (RCLK/CCLK network) and external (4 MHz TTL/CMOS) clock sources. For timing-critical applications requiring guaranteed 5 µs conversion time and minimal unit-to-unit variation, an external 4 MHz clock is recommended - the internal oscillator can vary ±50% due to process and temperature. External clocking also avoids accuracy degradation at longer conversion times (see Figure 14). The AD7575KP-REEL's CLK pin accepts standard logic levels and tolerates 30/70–70/30 duty cycle.

How does the AD7575KP-REEL interface with an 8085A-2 microprocessor in Slow Memory mode?

In Slow Memory mode, the AD7575KP-REEL connects to the 8085A-2 using CS and RD tied to the memory address decode and S0 status signal, respectively. A READ instruction asserts both lines, initiating conversion and forcing READY low via BUSY - halting the CPU until conversion completes. Data is then read in the same cycle. This requires no software delay loops and leverages the AD7575KP-REEL's 100 ns data access time and BUSY timing (t2 ≤ 100 ns). Interface details are shown in Figure 4 of the AD7575KP-REEL datasheet.