AD7801 Datasheet, PDF (4/16 Pages) Analog Devices – +2.7 V to +5.5 V, Parallel Input, Voltage Output 8-Bit DAC

AD7801
PIN CONFIGURATION
(MSB) DB7 1
20 DGND
DB6 2
DB5 3
19 V_OUT
18 NC
DB4 4
17 AGND
DB3 5 AD7801 16 REFIN
DB2
6
TOP VIEW
(Not to Scale)
15
V_DD
DB1 7
14 CLR
(LSB) DB0 8
13 LDAC
CS 9
12 PD
WR 10
11 DGND
NC = NO CONNECT
PIN FUNCTION DESCRIPTIONS
Pin
No. Mnemonic Function
1–8 D7–D0
9
CS
10 WR
11 DGND
12 PD
13 LDAC
14 CLR
15 V_DD
16 REFIN
17 AGND
18 NC
19
V_OUT
20 DGND
Parallel Data Inputs. 8-bit data is loaded to the input register of the AD7801 under the control of CS and WR.
Chip Select. Active low logic input.
Write Input. WR is an active low logic input used in conjunction with CS to write data to the input register.
Digital Ground
Active low input used to put the part into low power mode reducing current consumption to less than 1 µA.
Load DAC Logic Input. When this logic input is taken low the DAC output is updated with the contents of
its DAC register. If LDAC is permanently tied low the DAC is updated on the rising edge of WR.
Asynchronous Clear Input (Active Low). When this input is taken low the DAC register is loaded with all
zeroes and the DAC output is cleared to zero volts.
Power Supply Input. This part can be operated from +2.7 V to +5.5 V and should be decoupled to GND.
External Reference Input. This can be used as the reference for the DAC. The range on this reference input is
1 V to V_DD/2. If REFIN is tied directly to V_DD the internal V_DD/2 reference is selected.
Analog Ground reference point and return point for all analog current on the part.
No Connect Pin.
Analog Output Voltage from the DAC. The output amplifier can swing rail to rail on its output.
Digital Ground reference point and return point for all digital current on the part.
–4–
REV. 0