Datasheet
AD557–SPECIFICATIONS
Model Min Typ Max Unit
RESOLUTION 8 Bits
RELATIVE ACCURACY
0°C to 70°C ± 1/2 1 LSB
OUTPUT
Ranges 0 to 2.56 V
Current Source 5 mA
Sink Internal Passive
Pull-Down to Ground
2
OUTPUT SETTLING TIME
3
0.8 1.5 µs
FULL-SCALE ACCURACY
4
@ 25°C ± 1.5 ± 2.5 LSB
T
MIN
to T
MAX
± 2.5 ± 4.0 LSB
ZERO ERROR
@ 25°C ± 1 LSB
T
MIN
to T
MAX
± 3 LSB
MONOTONICITY
5
T
MIN
to T
MAX
Guaranteed But Not Tested
DIGITAL INPUTS
T
MIN
to T
MAX
Input Current ⴞ100 µA
Data Inputs, Voltage
Bit On—Logic “1” 2.0 V
Bit On—Logic “0” 0 0.8 V
Control Inputs, Voltage
On—Logic “1” 2.0 V
On—Logic “0” 0 0.8 V
Input Capacitance 4 pF
TIMING
6
t
W
Strobe Pulsewidth 225 ns
T
MIN
to T
MAX
300 ns
t
DH
Data Hold Time 10 ns
T
MIN
to T
MAX
10 ns
t
DS
Data Setup Time 225 ns
T
MIN
to T
MAX
300 ns
POWER SUPPLY
Operating Voltage Range (V
CC
)
2.56 Volt Range 4.5 5.5 V
Current (I
CC
)1525mA
Rejection Ratio 0.03 %/%
POWER DISSIPATION, V
CC
= 5 V 75 125 mW
OPERATING TEMPERATURE RANGE 0 70 °C
NOTES
1
Relative Accuracy is defined as the deviation of the code transition points from the
ideal transfer point on a straight line from the offset to the full scale of the device.
See “Measuring Offset Error” on the AD558 data sheet.
2
Passive pull-down resistance is 2 kΩ.
3
Settling time is specified for a positive-going full-scale step to ± 1/2 LSB. Negative-
going steps to zero are slower, but can be improved with an external pull-down.
4
The full-scale output voltage is 2.55 V and is guaranteed with a 5 V supply.
5
A monotonic converter has a maximum differential linearity error of ± 1 LSB.
6
See Figure 7.
Specifications shown in boldface are tested on all production units at electrical test.
Specifications subject to change without notice.
(@ T
A
= 25ⴗC, V
CC
= 5 V unless otherwise noted)
PIN CONFIGURATIONS
DIP
V
OUT
SENSE B
CS
CE
10
9
13
12
11
16
15
14
8
1
2
3
4
7
6
5
TOP VIEW
(Not to Scale)
AD557
GND
V
OUT
SENSE A
V
OUT
BIT 7
BIT 6
BIT 5
+V
CC
GNDBIT 4
BIT 3
BIT 2
(MSB) BIT 1
(LSB) BIT 8
PLCC
20 19123
4
5
6
7
8
9
10
11 12
13
TOP VIEW
(Not to Scale)
PIN 1
IDENTIFIER
18
14
15
16
17
BIT 6
BIT 5
NC
BIT 4
BIT 3
V
OUT
SENSE B
GND
NC
GND
+V
CC
AD557
V
OUT
SENSE A
BIT 7
V
OUT
NC
BIT 8 (LSB)
NC = NO CONNECT
BIT 2
(MSB) BIT 1
NC
CE
CS
REV. B
–2–
ORDERING GUIDE
Temperature Package Package
Model Range Description Option
AD557JN 0°C to 70°C Plastic DIP N-16
AD557JP 0°C to 70°C Plastic Leaded Chip Carrier P-20A
ABSOLUTE MAXIMUM RATINGS*
V
CC
to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 V to 18 V
Digital Inputs (Pins 1–10) . . . . . . . . . . . . . . . . . . . 0 V to 7.0 V
V
OUT
. . . . . . . . . . . . . . . . . . . . . . . Indefinite Short to Ground
Momentary Short to V
CC
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 mW
Storage Temperature Range
N/P (Plastic) Packages . . . . . . . . . . . . . . . . –25°C to +100°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . 300°C
Thermal Resistance
Junction to Ambient/Junction to Case
N/P (Plastic) Packages . . . . . . . . . . . . . . . . . .140/55°C/W
*Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.