Edge6420
HIGH-PERFORMANCE PRODUCTS – ATE
Circuit Description (continued)
Offset
The typical offset for each current DAC is governed by the
following equations:
K
* V
REF
128
GE
R_GAIN_E
I
=
–
OFFSET_E
*
MAX_COUNT_E
Equation 6.
I
= 0
OFFSET_F
Group E DACs
There are 2 Group E DACs/channel. Group E DACs are
characterized by:
• Current outputs (current flows out of the chip)
• 13 bit resolution
• Fixed offset (–128 * LSB typical)
• Adjustable full scale range (but < 3.6 mA).
The output current equation for Group E DACs is:
DATA
8192
200
3.125
I
=
–
OUT_E
*
R_GAIN_E
R_GAIN_E
where:
55 kΩ ≤ R_GAIN_E ≤ 156 kΩ
Note: V
= 2.5V
REF
Group F DACs
There are 3 Group F DACs/channel. Group F DACs are
characterized by:
• Current outputs (current flows out of the chip)
• 6 bit resolution
• Fixed offset (0 typical)
• Adjustable full scale range (but < 3.6 mA).
The output current equation for Group F DACs is:
DATA
64
200
I
=
OUT_F
*
R_GAIN_F
where:
55 kΩ ≤ R_GAIN_F ≤ 156 kΩ
Note: V
= 2.5V
REF
2000 Semtech Corp.
9
www .semtech.com
SEMTECH [ SEMTECH CORPORATION ]
