一文详解Maxim MAX1240低功耗12位模数转换器(ADC)解决方案

Maxim公司的MAX1240/MAX1241是低功耗12位模数转换器(ADC),8引脚封装, MAX1240工作电压+2.7V到+3.6V,内部基准电压2.5V;MAX1241工作电压2.7V-5.25V.12位分辨率, SPI/QSPI/MICROWIRE三线串行接口,主要用在电池供电的系统,手持数据记录和隔离数据采集,过程控制和仪表.本文介绍了MAX1240/MAX1241主要特性,框图,以及评估板MAX1240 EVK主要特性,材料清单和PCB设计图.

The MAX1240/MAX1241 low-power, 12-bit analog-to digital converters (ADCs) are available in 8-pin packages.

The MAX1240 operates with a single +2.7V to +3.6V supply, and the MAX1241 operates with a single +2.7V to +5.25V supply. Both devices feature a 7.5μs successive-approximation ADC, a fast track/hold (1.5μs), an on-chip clock, and a high-speed, 3-wire serial interface.

Power consumption is only 37mW (VDD = 3V) at the 73ksps maximum sampling speed. A 2μA shutdown mode reduces power at slower throughput rates.

The MAX1240 has an internal 2.5V reference, while the MAX1241 requires an external reference. The MAX1241 accepts signals from 0V to VREF, and the reference input range includes the positive supply rail. An external clock accesses data from the 3-wire interface, which connects directly to standard microcontroller I/O ports. The interface is compatible with SPI™, QSPI™, and MICROWIRE™.

Excellent AC characteristics and very low power combined with ease of use and small package size make these converters ideal for remote-sensor and data acquisition applications, or for other circuits with demanding power consumption and space requirements.

The MAX1240/MAX1241 are available in 8-pin PDIP and SO packages.

MAX1240/MAX1241主要特性:

♦ Single-Supply Operation:

+2.7V to +3.6V (MAX1240)

+2.7V to +5.25V (MAX1241)

♦ 12-Bit Resolution

♦ Internal 2.5V Reference (MAX1240)

♦ Small Footprint: 8-Pin PDIP/SO Packages

♦ Low Power: 3.7μW (73ksps, MAX1240)

3mW (73ksps, MAX1241)

66μW (1ksps, MAX1241)

5μW (power-down mode)

♦ Internal Track/Hold

♦ SPI/QSPI/MICROWIRE 3-Wire Serial Interface

♦ Internal Clock

MAX1240/MAX1241应用:

Battery-Powered Systems

Portable Data Logging

Isolated Data Acquisition

Process Control

Instrumentation

图1. MAX1240/MAX1241功能框图

评估板MAX1240 EVK

The MAX1240 evaluation kit (EV kit) demonstrates the MAX1240, low-power, 12-bit serial ADC. The MAX1240 peripheral module (Pmod™) and the USB2PMB2 module form a system, the MAX1240 EV kit. Windows XP, and Windows® 7/8/8.1/10-compatible software provides a user friendly interface that demonstrates features of the MAX1240.

The MAX1240 peripheral module comes installed with the 8-pin SO package, MAX1240ACSA++.

评估板MAX1240 EVK主要特性:

6-Pin PMod-Compatible Connector SPI)

On-Board Voltage Reference (MAX6126)

Proven PCB Layout

Fully Assembled and Tested

Windows XP, Windows 7/8/8.1/10-Compatible Software

图2. 评估板MAX1240 EVK外形图

图3. 评估板MAX1240 EVK电路图

评估板MAX1240 EVK材料清单:

图4. 评估板MAX1240 EVK PCB设计图(1):左:顶层丝印;右:顶层

图5. 评估板MAX1240 EVK PCB设计图(2):层2

图6. 评估板MAX1240 EVK PCB设计图(3):左:层3;右:底层