Ds4426 quad-channel, i, Power-supply tracking characteristics – Rainbow Electronics DS4426 User Manual
Page 4
DS4426
Quad-Channel, I
2
C-Margining IDACs with
Three Channels of Power-Supply Tracking
4
_______________________________________________________________________________________
Note 1: All voltages are referenced to GND. Current entering the IC is specified positive, and current exiting the IC is negative.
Note 2: Input resistors (R
FS[3:0]
) must be between the specified values to ensure the device meets its accuracy and linearity specifi-
cations.
Note 3: Supply current specified with all outputs set to zero current setting and with all inputs at V
CC
or GND. SDA and SCL are
connected to V
CC
. Excludes current through R
FS
resistors (I
RFS
). Total current including I
RFS
is I
CC
+ (2 x I
RFS
).
Note 4: The output-voltage full-scale ranges must be satisfied to ensure the device meets its accuracy and linearity specifications.
Only applies to current DAC operation, not power-supply tracking operation.
Note 5: Temperature drift excludes drift caused by external resistors.
Note 6: Differential linearity is defined as the difference between the expected incremental current increase with respect to position
and the actual increase. The expected incremental increase is the full-scale range divided by 127.
Note 7: Integral linearity is defined as the difference between the expected value as a function of the setting and the actual value.
The expected value is a straight line between the zero and the full-scale values proportional to the setting.
Note 8: Timing shown is for fast-mode operation (400kHz). This device is also backward-compatible with I
2
C standard-mode timing.
Note 9: C
B
—Total capacitance of one bus line in pF.
POWER-SUPPLY TRACKING CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C, see Figure 5.)
PARAMETER SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Divider Ratio
R
DIV
R
A
/R
B
and R
C
/R
D
0.5
1
Output Load
R
L
R
L
= (R
F
x R
E
)/(R
F
+R
E
) 1
20
k
Feedback Resistor Ratio
R
F
/R
B
0.5
4.5
Gain Resistor
R
G
0.8
10
k
Gain Setting Ratio
R
L
/R
G
1.4
5
R
L
/R
G
= 2, R
L
= 5k
, V
CC
= +3.6V,
T
A
= +25°C
2.4
Power-Supply Tracking Gain
G
VI
R
L
/R
G
= 5, R
L
= 5k
, V
CC
= +3.6V,
T
A
= +25°C
3.8 6.2 10
mA/V
Power-Supply Tracking Input
Bias Current
I
B
1
μA
Power-Supply Tracking Input
Voltage
V
IN
INP[3:1] and INN[3:1]
0
V
CC
-
1.4
V
Unity Gain Bandwidth
GBW
R
L
/R
G
= 1.4; R
L
= 5k
12 MHz
Output Voltage While Tracking
V
OUT:TRK
Switch closed, V
CC
= +3.0V, measured at
OUT[3:1], R
L
= 5k
0 1.5
V
Output Current While Tracking
I
OUT:TRK
R
L
/R
G
= 1.4, R
G
= 1k
, V
CC
= +3.0V,
V
FB
= +0.8V
1
mA
Tracking Accuracy
±600
mV
Output Leakage
I
BC
Switch open
0.5
μA
Comparator Input Bias Current
I
OFF
1
μA
Comparator Input Offset
V
OS
±5 mV
Switch Delay
t
DC
5 μs
Comparator Hysteresis
V
HYS
12.5
mV