AD7225KP-REEL Analog Devices Inc, AD7225KP-REEL Datasheet - Page 11

• Manufacturer Part Number: AD7225KP-REEL
• Description: IC DAC 8BIT QUAD W/AMP 28-PLCC
• Manufacturer: Analog Devices Inc

Specifications of AD7225KP-REEL

• Rohs Status: RoHS non-compliant
• Settling Time: 4µs
• Number Of Bits: 8
• Number Of Converters: 4
• Voltage Supply Source: Dual ±
• Power Dissipation (max): 500mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-LCC (J-Lead)
• Data Interface: -

GROUND MANAGEMENT AND LAYOUT
Because the AD7225 contains four reference inputs that can be
driven from ac sources (see the AC Reference Signal section),
careful layout and grounding is important to minimize analog
crosstalk between the four channels. The dynamic performance
of the four DACs depends on the optimum choice of board
layout. Figure 14 shows the relationship between input fre-
quency and channel-to-channel isolation. Figure 15 shows a
printed circuit board layout that minimizes crosstalk and
feedthrough. The four input signals are screened by AGND.
V
limiting effects from the output amplifier during measurements.
REF
was limited to between 2 V and 3.24 V to avoid slew rate
–80
–70
–60
–50
–40
–30
V
REF
20k
Figure 14. Channel-to-Channel Isolation
= 1.24V p-p
INPUT FREQUENCY (Hz)
50k
100k
200k
V
V
T
500k
A
DD
SS
= 25°C
= –5V
= +15V
1M
Rev. C | Page 11 of 24
Figure 15. Suggested PCB Layout for AD7225, Component Side (Top View)
V
V
V
V
AGND
DGND
OUT
OUT
REF
REF
V
SS
B
A
B
A
MSB
PIN 1
SYSTEM
GND
LSB
V
V
V
V
V
OUT
OUT
DD
REF
REF
C
D
C
D
AD7225