The AD4000 is a low noise, low power, high speed, 16-bit, 2 MSPS precision successive approximation register (SAR) analog-to-digital converter (ADC). It incorporates ease of use features that lower the signal chain power, reduce signal chain complexity, and enable higher channel density. The high-Z mode, coupled with a long acquisition phase, eliminates the need for a dedicated high power, high speed ADC driver, thus broadening the range of low power precision amplifiers that can drive this ADC directly while still achieving optimum performance. The input span compression feature enables the ADC driver amplifier and the ADC to operate off common supply rails without the need for a negative supply while preserving the full ADC code range. The low serial peripheral interface (SPI) clock rate requirement reduces the digital input/output power consumption, broadens processor options, and simplifies the task of sending data across digital isolation.
Operating from a 1.8 V supply, the AD4000 samples an analog input (IN+) between 0 V to VREF with respect to a ground sense (IN−) with VREF ranging from 2.4 V to 5.1 V. The AD4000 consumes only 14 mW at 2 MSPS with a minimum of 70 MHz SCK rate in turbo mode and achieves ±1.0 LSB INL maximum, no missing codes at 16 bits with 93 dB SNR. The reference voltage is applied externally and can be set independently of the supply voltage.
The SPI-compatible versatile serial interface features seven different modes including the ability, using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provides an optional busy indicator. The AD4000 is compatible with 1.8 V, 2.5 V, 3 V, and 5 V logic, using the separate VIO supply.
The AD4000 is available in a 10-lead MSOP or a 10-lead LFCSP with operation specified from −40°C to +125°C. The device is pin compatible with the 18-bit, 2 MSPS AD4003.
**Applications**
Automatic test equipment
Machine automation
Medical equipment
Battery-powered equipment
Precision data acquisition systems
### Features and Benefits
Throughput: 2 MSPS maximum
INL: ±1.0 LSB maximum
Guaranteed 16-bit no missing codes
Low power
9.75 mW at 2 MSPS (VDD only)
70 μW at 10 kSPS, 14 mW at 2 MSPS (total)
SNR: 93 dB typical at 1 kHz, 90 dB typical at 100 kHz
THD: −115 dB typical at 1 kHz, −95 dB typical at 100 kHz
Ease of use features reduce system power and complexity
Input overvoltage clamp circuit
Reduced nonlinear input charge kickback
High-Z mode
Long acquisition phase
Input span compression
Fast conversion time allows low SPI clock rates
SPI-programmable modes, read/write capability, status word
Pseudo differential (single-ended) analog input range: 0 V to VREF with VREF between 2.4 V to 5.1 V
Single 1.8 V supply operation with 1.71 V to 5.5 V logic interface
SAR architecture: no latency/pipeline delay
Guaranteed operation: −40°C to 125°C
Serial interface SPI-/QSPI-/MICROWIRE-/DSP-compatible
Ability to daisy-chain multiple ADCs and busy indicator
10-lead package: 3 mm × 3 mm LFCSP and 3 mm × 4.90 mm MSOP
