Analog-to-digital converter application circuit design analysis

An analog-to-digital converter, or ADC for short, usually refers to an electronic component that converts analog signals into digital signals. A typical analog-to-digital converter converts an input voltage signal into an output digital signal. This article introduces the circuit principles of several analog-to-digital converter chips.

1. AD9280

The AD9280 device is a single-chip, 8-bit, 32 MSPS analog-to-digital converter (ADC). This article mainly introduces the AD9280 features, application range, reference design circuit and circuit analysis to help you shorten design time.

AD9280 introduction:

The AD9280 is a single-chip, 8-bit, 32 MSPS analog-to-digital converter (ADC) that operates from a single supply and includes an on-chip sample-and-hold amplifier and voltage reference. It uses a multi-stage differential pipeline architecture with a data rate of 32 MSPS and no missing codes over the entire operating temperature range.

AD9280 features:

Pin compatible with AD876-8

Power consumption: 95 mW (3 V power supply)

Operating voltage range: +2.7V to +5.5V

Differential nonlinearity (DNL) error: 0.2 LSB

Power saving (sleep) mode

AD9280 internal structure block diagram:

Figure 1 Internal structural block diagram of AD9280, showing the internal structure

AD9280 reference design circuit:

Figure 2 AD9280 typical application circuit

2.AD7541

The AD7541 device is a low-cost, high-performance 12-bit single-chip multiplying digital-to-analog converter. This article mainly introduces the AD7541 characteristics, application range, reference design circuit and circuit analysis to help everyone shorten design time.

AD7541 introduction:

The AD7541A is a low-cost, high-performance 12-bit single-chip multiplying digital-to-analog converter. The device is manufactured using advanced low-noise thin film CMOS technology and is available in standard 18-pin DIP and 20-pin surface mount packages. The AD7541A is functionally and pin-compatible with the industry standard device AD7541, and has improved specifications and performance. Additionally, improvements in device design ensure that latch-up does not occur, eliminating the need for output protection Schottky diodes.

AD7541 features:

Improved version of AD7541

Complete four-quadrant multiplication

12-bit linearity (endpoint)

All devices are guaranteed to be monotonic

TTL/CMOS compatible

low cost

No protection Schottky diode required

Low logic input leakage

AD7541 internal structure block diagram:

Figure 3 Internal structural block diagram of AD7541, showing the internal structure

AD7541 reference design circuit:

Figure 4 AD7541 typical application circuit

3.AD7694

The AD7694 device is a 3-channel, low-noise, low-power consumption, 24-bit Σ-Δ ADC with a built-in on-chip instrumentation amplifier. This article mainly introduces the AD7694 characteristics, application range, reference design circuit and circuit analysis to help you shorten the design time. .

AD7694 introduction:

The AD7694 is a 16-bit, 250 kSPS, charge redistribution, successive approximation analog-to-digital converter (ADC) that operates from a single 2.7 V to 5.25 V supply (VDD). The device incorporates an extremely low-power, high-speed, 16-bit no-missing-code sampling ADC (Grade B), an internal conversion clock, and an SPI-compatible serial interface port. It also integrates a low-noise, wide-bandwidth, extremely short aperture delay sample and hold circuit. On the rising edge of CNV, the AD7694 samples the analog input voltage difference between IN+ and IN-, ranging from 0V to REF. The reference voltage (REF) is provided externally and can be set up to the supply voltage.

AD7694 features:

16-bit resolution

Throughput: 250 kSPS

Integral nonlinearity (INL): ±4 LSB maximum

Power consumption:

800 µA @ 5V/100kSPS

540 µA @ 2.7V/100kSPS

Pseudo-differential analog input range: 0 V ~ VREF (VREF is up to VDD)

AD7694 applications:

battery powered equipment

Medical equipment

mobile communications

personal digital assistant

data collection

Instrumentation

process control

AD7694 reference design circuit:

Figure 5 AD7694 typical application circuit

Editor's comment: This article mainly introduces the characteristics, application range, reference design circuit and circuit analysis of AD9280, AD7541 and AD7694 to help everyone shorten design time. The AD9280 is a single-chip, 8-bit, 32 MSPS analog-to-digital converter (ADC) that operates from a single supply and includes an on-chip sample-and-hold amplifier and voltage reference. The AD7541A is a low-cost, high-performance 12-bit single-chip multiplying digital-to-analog converter. The AD7694 is a 16-bit, 250 kSPS, charge redistribution, successive approximation analog-to-digital converter (ADC) that operates from a single 2.7 V to 5.25 V supply (VDD).