Rainbow Electronics MAX5121 - Manual (Page 8)

MAX5120/MAX5121
+3V/+5V, 12-Bit, Serial Voltage-Output DACs
with Internal Reference
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V DD = +5V (MAX5120), V DD = +3V (MAX5121), R L = 5k Ω , C L = 100pF, OS = AGND, T
A
= +25°C, unless otherwise noted.)
CS
2V/div
OUT
500mV/div
2 µ s/div
MAX5121
DYNAMIC RESPONSE FALL TIME
MAX5120/21-22
SCLK
2V/div
OUT
500
µ V/div
AC COUPLED
2 µ s/div
MAX5121
DIGITAL FEEDTHROUGH (SCLK, OUT)
MAX5120/21-23
CS
2V/div
OUT
100mV/div
AC COUPLED
5 µ s/div
MAX5121
MAJOR CARRY TRANSITION
MAX5120/21-24
Pin Description
PIN
Offset Adjust (Analog Input) OS 1
FUNCTION NAME
Analog Output Voltage. High impedance if part is in shutdown. OUT 2
Power-Down Lockout (Digital Input)
1: Normal operation.
0: Disallows shutdown (device cannot be powered down).
PDL 4
Reset Value Input (Digital Input)
1: Tie to V
DD to select midscale as the output reset value.
0: Tie to DGND to select 0V as the output reset value.
RSTVAL 3
Active-Low Chip-Select Input (Digital Input) CS 6
Serial Clock Input SCLK 8
Serial Data Input. Data is clocked in on the rising edge of SCLK. DIN 7
Reset DAC Input (Digital Input). Clears the DAC to its predetermined (RSTVAL) output state. Clearing the
DAC will cause it to exit a software shutdown state.
CLR 5
Serial Data Output DOUT 10
Power-Down Input (Digital Input). Pulling PD high when PDL = V DD places the IC into shutdown with a
maximum shutdown current of 20µA.
PD 12
User-Programmable Output (Digital Output) UPO 11
Buffered Reference Output/Input. In internal reference mode, the reference buffer provides a +2.5V
(MAX5120) or +1.25V (MAX5121) nominal output, externally adjustable at REFADJ. In external reference
mode, disable the internal reference by pulling REFADJ to V
DD and applying the external reference to REF.
REF 14
Positive Power Supply. Bypass with a 0.1µF capacitor in parallel with a 4.7µF capacitor to AGND. V DD 16
Analog Reference Adjust Input. Bypass with a 33nF capacitor to AGND. Connect to V DD when using an
external reference.
REFADJ 15
Analog Ground AGND 13
Digital Ground DGND 9