Datasheet

MAX1220/MAX1257/MAX1258
12-Bit, Multichannel ADCs/DACs with FIFO,
Temperature Sensing, and GPIO Ports
16 ______________________________________________________________________________________
Pin Description
PIN
MAX1220
MAX1257
MAX1258
NAME FUNCTION
1, 2 — GPIOA0, GPIOA1 General-Purpose I/O A0, A1. GPIOA0, A1 can sink and source 15mA.
3 4 EOC
Active-Low End-of-Conversion Output. Data is valid after the falling edge
of EOC.
4 7 DVDD
Digital Positive-Power Input. Bypass DVDD to DGND with a 0.1µF
capacitor.
5 8 DGND Digital Ground. Connect DGND to AGND.
6 9 DOUT
Serial-Data Output. Data is clocked out on the falling edge of the SCLK
clock in modes 00, 01, and 10. Data is clocked out on the rising edge of
the SCLK clock in mode 11. It is high impedance when CS is high.
7 10 SCLK
Serial-Clock Input. Clocks data in and out of the serial interface. (Duty
cycle must be 40% to 60%.) See Table 5 for details on programming the
clock mode.
8 11 DIN
Serial-Data Input. DIN data is latched into the serial interface on the
falling edge of SCLK.
9–12, 16–19
12–15,
22–25
OUT0–OUT7 DAC Outputs
13 18 AVDD
Positive Analog Power Input. Bypass AVDD to AGND with a 0.1µF
capacitor.
14 19 AGND Analog Ground
15, 23, 32, 33 — N.C. No Connection. Not internally connected.
20 26 LDAC
Active-Low Load DAC. LDAC is an asynchronous active-low input that
updates the DAC outputs. Drive LDAC low to make the DAC registers
transparent.
21 27 CS
Active-Low Chip-Select Input. When CS is low, the serial interface is
enabled. When CS is high, DOUT is high impedance.
22 28 RES_SEL
Reset Select. Select DAC wake-up mode. Set RES_SEL low to wake up
the DAC outputs with a 100k resistor to AGND or set RES_SEL high to
wake up the DAC outputs with a 100k resistor to V
REF
. Set RES_SEL
high to power up the DAC input register to FFFh. Set RES_SEL low to
power up the DAC input register to 000h.
24, 25 — GPIOC0, GPIOC1 General-Purpose I/O C0, C1. GPIOC0, C1 can sink 4mA and source 2mA.