ADI ADT7516数字温度计方案

ADI公司的ADT7516/ADT7517/ADT75191是SPI/I2C兼容的温度传感器，有4路10位ADC和4路12-/10-/8位DAC电压输出，温度分辨率为0.25度C，工作电压2.7 V 到5.5 V,可广泛应用在手提以电池为能源的仪表，个人计算机，智能电池充电器，通信系统，测试设备以及过程控制等。本文介绍了ADT7516的主要特性以及功能方框图，以及ADT7516评估板的主要特性和详细的电路图和所采用的元件清单（BOM）。

ADT7516:  SPI/I2C Compatible, Temperature Sensor, 4-Channel ADC and Quad Voltage Output
The ADT7516/ADT7517/ADT75191 combines a 10-bit temperature-to-digital converter, a 10-bit 4-channel ADC, and a quad 12-/10-/8-bit DAC, respectively, in a 16-lead QSOP package. The parts also include a band gap temperature sensor and a 10-bit ADC to monitor and digitize the temperature reading to a resolution of 0.25°C.
The ADT7516/ADT7517/ADT7519 operate from a single 2.7 V to 5.5 V supply. The input voltage range on the ADC channels is 0 V to 2.28 V, and the input bandwidth is dc. The reference for the ADC channels is derived internally. The output voltage of the DAC ranges from 0 V to VDD, with an output voltage settling time of 7 μs typical.
The ADT7516/ADT7517/ADT7519 provide two serial interface options: a 4-wire serial interface that is compatible with SPI, QSPI, MICROWIRE, and DSP interface standards, and a 2-wire SMBus/I2C interface. They feature a standby mode that is controlled through the serial interface.

The reference for the four DACs is derived either internally or from a reference pin. The outputs of all DACs can be updated simultaneously using the software LDAC function or the external LDAC  pin. The ADT7516/ADT7517/ADT7519 incorporate a power-on reset circuit, ensuring that the DAC output powers up to 0 V and remains there until a valid write takes place.

The wide supply voltage range, low supply current, and SPI-/ I2C-compatible interface of the ADT7516/ADT7517/ADT7519 make them ideal for a variety of applications, including personal computers, office equipment, and domestic appliances.

ADT7516主要特性：
ADT7516: four 12-bit DACs
ADT7517: four 10-bit DACs
ADT7519: four 8-bit DACs
Buffered voltage output
Guaranteed monotonic by design over all codes
10-bit temperature-to-digital converter
10-bit 4-channel ADC
C input bandwidth
Input range: 0 V to 2.28 V
Temperature range: −40°C to +120°C
Temperature sensor accuracy: ±0.5°C typ
Supply range: 2.7 V to 5.5 V
DAC output range: 0 V to 2 VREF
Power-down current: <10 μA
Internal 2.28 VREF option
Double-buffered input logic
Buffered reference input
Power-on reset to 0 V DAC output
Simultaneous update of outputs (LDAC function)
On-chip, rail-to-rail output buffer amplifier
SPI&reg;, I2C&reg;, QSPI&#8482;, MICROWIRE&#8482;, and DSP compatible
4-wire serial interface
SMBus packet error checking (PEC) compatible
16-lead QSOP package
APPLICATIONS
Portable battery-powered instruments
Personal computers
Smart battery chargers
Telecommunications systems
Electronic text equipment
Domestic appliances
Process control



图1。ADT7516/ADT7517/ADT7519功能方框图

ADT7516评估板
The ADT7516 evaluation board allows the ADT7516 digital temperature sensor, 4-channel ADC and quad DAC to be quickly and easily evaluated using a PC. Using the evaluation board and its accompanying software, the ADT7516 evaluation board can be interfaced to any PC running Windows&reg; XP, Windows 2000 or higher, via one of the computer’s USB ports. The two other parts in the family, the ADT7517 and ADT7519, differ only in that they have 10-bit and 8-bit DACs, respectively. The ADT7516 evaluation board can be used to emulate the ADT7517 by setting the two LSBs of the DACs to zero and for the ADT7519 by setting the four LSBs of the DACs to zero.

The evaluation board allows all the input and output functions of the ADT7516 to be exercised without the need for external components. The software allows control and monitoring of the ADT7516’s internal registers.

The ADT7516/ADT7517/ADT7519 combine a 10-bit temperature-to-digital converter and a quad 12-/10-/8-bit DAC, respectively, in a 16-lead QSOP. This includes a band gap temperature sensor and a 10-bit ADC to monitor and digitize the temperature reading to a resolution of 0.25°C. The ADT7516/ ADT7517/ADT7519 operate from a single 2.7 V to 5.5 V supply. The input voltage range on the ADC channels is 0 V to 2.28 V, and the input bandwidth is dc. The reference for the ADC channels is derived internally. The output voltage of the DAC ranges from 0 V to VDD, with an output voltage settling time of typically 7 ms.
The ADT7516/ADT7517/ADT7519 provide two serial inter- face options, a 4-wire serial interface that is compatible with SPI, QSPI&#8482;, MICROWIRE&#8482;, and DSP interface standards and a 2-wire SMBus/I2C interface. These products feature a standby mode that is controlled via the serial interface.