- 您现在的位置：买卖IC网 > PDF目录1935 > MAX1257BETM+T (Maxim Integrated Products)IC ADC/DAC 12BIT 48-TQFN PDF资料下载
参数资料
| 型号： | MAX1257BETM+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 16/43页 |
| 文件大小： | 0K |
| 描述： | IC ADC/DAC 12BIT 48-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | ADC，DAC |
| 分辨率（位）： | 12 b |
| 采样率（每秒）： | 225k |
| 数据接口： | 串行 |
| 电压电源： | 模拟和数字 |
| 电源电压： | 2.7 V ~ 3.6 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 48-WFQFN 裸露焊盘 |
| 供应商设备封装： | 48-TQFN-EP（7x7） |
| 包装： | 带卷 (TR) |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页当前第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页
MAX1220/MAX1257/MAX1258
12-Bit, Multichannel ADCs/DACs with FIFO,
Temperature Sensing, and GPIO Ports
______________________________________________________________________________________
23
GPIOB3, and GPIOC0–GPIOC3. The MAX1220 includes
four GPIO channels (GPIOA0, GPIOA1, GPIOC0,
GPIOC1). Read and write to the GPIOs as detailed in
Table 1 and Tables 12–19. Also, see the
GPIO Command
section. See Figures 11 and 12 for GPIO timing.
Write to the GPIOs by writing a command byte to the
GPIO command register. Write a single data byte to the
MAX1220 following the command byte. Write 2 bytes to
the MAX1257/MAX1258 following the command byte.
The GPIOs can sink and source current. The
MAX1257/MAX1258 GPIOA0–GPIOA3 can sink and
source up to 15mA. GPIOB0–GPIOB3 and GPIOC0–
GPIOC3 can sink 4mA and source 2mA. The MAX1220
GPIOA0 and GPIOA1 can sink and source up to 15mA.
The MAX1220 GPIOC0 and GPIOC1 can sink 4mA and
source 2mA. See Table 3.
Clock Modes
Internal Clock
The MAX1220/MAX1257/MAX1258 can operate from an
internal oscillator. The internal oscillator is active in
clock modes 00, 01, and 10. Figures 6, 7, and 8 show
how to start an ADC conversion in the three internally
timed conversion modes.
Read out the data at clock speeds up to 25MHz
through the SPI interface.
External Clock
Set CKSEL1 and CKSEL0 in the setup register to 11 to
set up the interface for external clock mode 11. See
Table 5. Pulse SCLK at speeds from 0.1MHz to
3.6MHz. Write to SCLK with a 40% to 60% duty cycle.
The SCLK frequency controls the conversion timing.
See Figures 9a and 9b for clock mode 11 timing. See
the
ADC Conversions in Clock Mode 11 section.
ADC/DAC References
Address the reference through the setup register, bits 3
and 2. See Table 5. Following a wake-up delay, set
REFSEL[1:0] = 00 to program both the ADC and DAC
for internal reference use. Set REFSEL[1:0] = 10 to pro-
gram the ADC for internal reference. Set REFSEL[1:0] =
10 to program the DAC for external reference, REF1.
When using REF1 or REF2/AIN_ in external-reference
mode, connect a 0.1F capacitor to AGND. Set
REFSEL[1:0] = 01 to program the ADC and DAC for
external-reference mode. The DAC uses REF1 as its
external reference, while the ADC uses REF2 as its
external reference. Set REFSEL[1:0] = 11 to program
the ADC for external differential reference mode. REF1
is the positive reference and REF2 is the negative refer-
ence in the ADC external differential mode.
When REFSEL[1:0] = 00 or 10, REF2/AIN_ functions as
an analog input channel. When REFSEL[1:0] = 01 or 11,
REF2/AIN_ functions as the device’s negative reference.
Temperature Measurements
Issue a command byte setting bit 0 of the conversion
register to one to take a temperature measurement.
See Table 4. The MAX1220/MAX1257/MAX1258 perform
temperature measurements with an internal diode-con-
nected transistor. The diode bias current changes from
68A to 4A to produce a temperature-dependent bias
voltage difference. The second conversion result at 4A
is subtracted from the first at 68A to calculate a digital
value that is proportional to absolute temperature. The
output data appearing at DOUT is the digital code
above, minus an offset to adjust from Kelvin to Celsius.
The reference voltage used for the temperature mea-
surements is always derived from the internal reference
source to ensure that 1 LSB corresponds to 1/8 of a
degree Celsius. On every scan where a temperature
measurement is requested, the temperature conversion
is carried out first. The first 2 bytes of data read from
the FIFO contain the result of the temperature measure-
ment. If another temperature measurement is per-
formed before the first temperature result is read out,
the old measurement is overwritten by the new result.
Temperature results are in degrees Celsius (two’s com-
plement). See the
Applications Information section for
information on how to perform temperature measure-
ments in each clock mode.
Register Descriptions
The MAX1220/MAX1257/MAX1258 communicate
between the internal registers and the external circuitry
through the SPI-compatible serial interface. Table 1
details the command byte, the registers, and the bit
Table 3. GPIO Maximum Sink/Source Current
MAX1257/MAX1258 (mA)
MAX1220 (mA)
CURRENT
GPIOA0–GPIOA3
GPIOB0–GPIOB3
GPIOC0–GPIOC3
GPIOA0, GPIOA1
GPIOC0, GPIOC1
Sink
15
4
15
4
Source
15
2
15
2
相关PDF资料 |
PDF描述 |
|---|---|
| MAX125CCAX+D | IC DAS 14BIT 2X4CH 36-SSOP |
| MAX1271AENG+ | IC ADC 12BIT 8CH 24-DIP |
| MAX127AENG+ | IC DAS 12BIT 2-WIRE 24-DIP |
| MAX13021ASA+ | IC TRANSCEIVER LIN 8-SOIC |
| MAX13036ATI+T | IC CONTACT MONITOR AUTO 28-TQFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1257EVKIT | 功能描述:数据转换 IC 开发工具 Programmers, Development Systems RoHS:否 制造商:Texas Instruments 产品:Demonstration Kits 类型:ADC 工具用于评估:ADS130E08 接口类型:SPI 工作电源电压:- 6 V to + 6 V |
| MAX1258BETM | 功能描述:ADC / DAC多通道 RoHS:否 制造商:Texas Instruments 转换速率: 分辨率:8 bit 接口类型:SPI 电压参考: 电源电压-最大:3.6 V 电源电压-最小:2 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-40 |
| MAX1258BETM+ | 功能描述:ADC / DAC多通道 12-Bit 16Ch 300ksps 5.5V Precision ADC RoHS:否 制造商:Texas Instruments 转换速率: 分辨率:8 bit 接口类型:SPI 电压参考: 电源电压-最大:3.6 V 电源电压-最小:2 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-40 |
| MAX1258BETM+T | 功能描述:ADC / DAC多通道 12-Bit 16Ch 300ksps 5.5V Precision ADC RoHS:否 制造商:Texas Instruments 转换速率: 分辨率:8 bit 接口类型:SPI 电压参考: 电源电压-最大:3.6 V 电源电压-最小:2 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-40 |
| MAX1258BETM-T | 功能描述:ADC / DAC多通道 RoHS:否 制造商:Texas Instruments 转换速率: 分辨率:8 bit 接口类型:SPI 电压参考: 电源电压-最大:3.6 V 电源电压-最小:2 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-40 |
发布紧急采购，3分钟左右您将得到回复。