AS1520, AS1521
1 0 - B i t , S i n g l e - S u p p l y, L o w - P o w e r, 4 0 0 / 3 0 0 k s ps ,
8-Channel A/D Converters
Product Brief
1 General Description
The AS1520/AS1521 are low-power, 8/4-channel, 400/
300ksps, 10-bit analog-to-digital (A/D) converters specif-
ically designed to operate with single-supply devices.
Superior AC characteristics, very low power consump-
tion, and highly-reliable packaging make these ultra-
small devices perfect for battery-powered remote-sen-
sor and data-acquisition devices.
The successive-approximation register (SAR), high-
speed sampling, high-bandwidth track/hold circuitry, and
multi-mode operation combine to make these devices
highly-flexible and configurable.
Both devices require low supply current (2.8mA @
400ksps, AS1520; 2.2mA @ 300ksps, AS1521) and fea-
ture a reduced-power mode and a power-down mode to
lower power consumption at slower throughput rates.
The devices operate from a single supply (+4.5 to +5.5V,
AS1520; +2.7 to +3.6V, AS1521). Both devices contain
an internal 2.5V reference, an integrated reference
buffer, and feature support for an external reference (1V
to V
DD
).
Data accesses are made via the high-speed, 4-wire,
SPI, QSPI-, and Microwire-compatible serial interface.
The devices are available in a 20-pin TSSOP package.
2 Key Features
!
Single-Supply Operation:
- +4.5 to +5.5V (AS1520)
- +2.7 to +3.6V (AS1521)
Sampling Rate:
- 400ksps (AS1520)
- 300ksps (AS1521)
Software-Configurable Analog Input Types:
- 8-Channel Single-Ended
- 8-Channel Pseudo Differential Referenced to COM
- 4-Channel Pseudo Differential
- 4-Channel Fully Differential
Software-Configurable Input Range
Internal +2.5V Reference
Low-Current Operation:
- 2.8mA @ 400ksps (AS1520)
- 2.2mA @ 300ksps (AS1521)
- 0.4mA in Reduced-Power Mode
- 0.5µA in Full Power-Down Mode
SPI/QSPI/Microwire/TMS320-Compatible
20-pin TSSOP Package
!
!
!
!
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3 Applications
The devices are ideal for remote sensors, data-acquisi-
tion and data-logging devices, pen-digitizers, process
control, or any other space-limited A/D application with
low power-consumption requirements.
14
Figure 1. Block Diagram and Pin Assignments
17
CSN
18
SCLK
16
DIN
Input Shift
Register
Output
Shift
Register
DOUT
15
SSTRB
CH0 1
CH1 2
20 V
DD1
19 V
DD2
18 SCLK
17 CSN
AS1520/
AS1521
10-Bit
SAR
10
V
DD3
19
V
DD2
CH2 3
CH3 4
CH4 5
CH5 6
CH6 7
Control
Logic
1:8
CH0:CH7
9
COM
+1.2V
REF
Analog
Input
Track/
Hold
17kΩ
Av
≈
2.05
+2.50V
IN
AS1520/
AS1521
16 DIN
15 SSTRB
14 DOUT
13 GND
12 REFADJ
11 REF
OUT
REF
20
V
DD1
CH7 8
COM 9
V
DD3
10
12
REFADJ
11
REF
13
GND
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Revision 1.00
1-2
AMSCO [ AUSTRIAMICROSYSTEMS AG ]
