5962-8686101XA Datasheet, PDF (7/8 Pages) Analog Devices – High Precision, 2.5 V IC Reference

THE AD580 AS A LOW POWER, LOW VOLTAGE,
PRECISION REFERENCE FOR DATA CONVERTERS
The AD580 has a number of features that make it ideally suited
for use with A/D and D/A data converters used in complex
microprocessor-based systems. The calibrated 2.500 V output
minimizes user trim requirements and allows operation from a
single, low voltage supply. Low power consumption (1 mA
quiescent current) is commensurate with that of CMOS-type
devices, while the low cost and small package complements the
decreasing cost and size of the latest converters.
Figure 12 shows the AD580 used as a reference for the AD7542
12-bit CMOS DAC with complete microprocessor interface.
The AD580 and the AD7542 are specified to operate from a
single 5 V supply, thus eliminating the need to provide a 15 V
power supply for the sole purpose of operating a reference. The
AD7542 includes three 4-bit data registers, a 12-bit DAC
register, and address decoding logic. It may thus be interfaced
directly to a 4-, 8- or 16-bit data bus. Only 8 mA of quiescent
current from the single 5 volt supply is required to operate the
AD7542 which is packaged in a small, 16-pin DIP. The AD544
AD580
output amplifier is also low power, requiring only 2.5 mA
quiescent current. Its laser-trimmed offset voltage preserves the
±1/2 LSB linearity of the AD7542KN without user trims, and it
typically settles to ±1/2 LSB in less than 3 µs. It will provide the
0 V to –2.5 V output swing from ±5 V supplies.
+5V
+E
AD580 ^EOUT
SYSTEM
8-BIT DATA BUS
D0
D1
D2
D3
–E _500Ω
GAIN
ADJUST
V_DD
14
7
6
5
AD7542
V_REF
15
200Ω
RFB
16
I_OUT1
1
2
I_OUT2
4
3
AD7
AD0
13 10 11 9 8 12
CLR A0 A1 WR CS
AGND
22pF
AD544L
–5V
ANALOG
INPUT
FROM SYSTEM RESET
A0
FROM ADDRESS BUS
A1
DGND
FROM WR
FROM ADDRESS DECODER
Figure 12. Low Power, Low Voltage Reference for the AD7542
Microprocessor-Compatible, 12-Bit DAC
Rev. B | Page 7 of 8