AD5557 Analog Devices, AD5557 Datasheet - Page 8

• Manufacturer Part Number: AD5557
• Description: Dual Current Output, Parallel Input, 14-Bit Multiplying DACs with 4-Quadrant Resistors
• Manufacturer: Analog Devices

Specifications of AD5557

• Resolution (bits): 14bit
• Dac Update Rate: 2MSPS
• Dac Settling Time: 500ns
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Current Out
• Dac Input Format: Par

AD5547/AD5557
Table 4.
Pin No.
1, 2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
AD5557
Mnemonic
NC
R
R
R
R
V
I
AGNDA
DGND
AGNDB
I
V
R
R
R
R
WR
A0
A1
LDAC
MSB
OUTA
OUTB
OFSA
FBA
1A
COMA
REFA
REFB
COMB
1B
FBB
OFSB
Pin Function Descriptions
Function
No Connection. Do not connect anything other than the dummy pads to these pins.
Bipolar Offset Resistor A. Accepts up to ±18 V. In 2-quadrant mode, R
ties to R
Internal Matching Feedback Resistor A. Connects to the external op amp for I-to-V conversion.
4-Quandrant Resistor. In 2-quadrant mode, R
not connect when operating in unipolar mode.
Center Tap Point of the Two 4-Quadrant Resistors, R
node of the reference amplifier. In 2-quadrant mode, R
in unipolar mode.
DAC A Reference Input in 2-Quadrant Mode, R2 Terminal in 4-Quadrant Mode. In 2-quadrant mode, V
reference input with constant input resistance vs. code. In 4-quadrant mode, V
reference amplifier.
DAC A Current Output. Connects to the inverting terminal of external precision I-to-V op amp for voltage
output.
DAC A Analog Ground.
Digital Ground.
DAC B Analog Ground.
DAC B Current Output. Connects to inverting terminal of external precision I-to-V op amp for voltage output.
DAC B Reference Input Pin. Establishes DAC full-scale voltage. Constant input resistance vs. code. If configured
with an external op amp for 4-quadrant multiplying, V
Center Tap Point of the Two 4-Quadrant Resistors, R
node of the reference amplifier. In 2-quadrant mode, R
in unipolar mode.
4-Quandrant Resistor. In 2-quadrant mode, R
not connect if operating in unipolar mode.
Internal Matching Feedback Resistor B. Connects to external op amp for I-to-V conversion.
Bipolar Offset Resistor B. Accepts up to ±18 V. In 2-quadrant mode, R
ties to R
Write Control Digital Input In, Active Low. Transfers shift register data to the DAC register on the rising edge.
Signal level must be ≤V
Address Pin 0. Signal level must be ≤V
Address Pin 1. Signal level must be ≤V
Digital Input Load DAC Control. Signal level must be ≤V
Power-On Reset State. MSB = 0 corresponds to zero-scale reset; MSB = 1 corresponds to midscale reset. The
signal level must be ≤V
1A
1B
and an external reference.
and the external reference.
AGNDA
AGNDB
R
R
R
R
DGND
V
V
I
I
COMB 14
COMA
R
DD
R
OUTB 12
OFSA
OUTA
REFB 13
OFSB 17
DD
REFA
R
R
FBA
FBB 16
WR
NC
NC
A0
1B 15
1A
+ 0.3 V.
+ 0.3 V.
Figure 5.
10
11
18
19
1
2
3
4
5
6
7
8
9
Rev. C | Page 8 of 20
NC = NO CONNECT
AD5557
(Not to Scale)
AD5557
TOP VIEW
DD
DD
+ 0.3 V.
+ 0.3 V.
Pin Configuration
1A
1B
shorts to the V
shorts to the V
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
1A
1B
and R
and R
D0
D1
D2
D3
D4
D5
D6
D7
D8
VDD
D9
D10
D11
D12
D13
RS
MSB
LDAC
A1
REFB
COMA
COMB
DD
becomes –V
+ 0.3 V.
shorts to the V
shorts to the V
2A
2B
. In 4-quadrant mode, R
. In 4-quadrant mode, R
REFB
REFA
pin. In 4-quadrant mode, R
pin. In 4-quadrant mode, R
OFSB
OFSA
REF
.
ties to R
ties to R
REFB
REFA
pin. Do not connect if operating
pin. Do not connect if operating
REFA
FBB
FBA
is driven by the external
. In 4-quadrant mode, R
. In 4-quadrant mode, R
COMB
COMA
ties to the inverting
ties to the inverting
1B
1A
Data Sheet
ties to R
ties to R
REFA
OFSB
OFSA
is the
. Do
. Do
OFSB
OFSA