|NE5410F||10-Bit high-speed multiplying D/A converter|
|NE5410F Datasheet PDF : 9 Pages |
Philips Semiconductors Linear Products
10-Bit high-speed multiplying D/A converter
D1 THROUGH D10
R16 + RT = R15 = RREF
RT < <R16
IO F.S. = 2 IR = VREF/RREF a. Positive Reference Voltage
D1 THROUGH D10
R15 + RT = R16
RT < <R15
IVREF ≥ RVEE + 3V
b. Negative Reference Voltage
Figure 6. Basic Connections
OUTPUT VOLTAGE COMPLIANCE
The output voltage compliance ranges from -2.5 to +2.5V. As shown
in Figure 2, this compliance range is nearly constant over
temperature. At the temperature extremes, however, the compliance
voltage may be reduced if VEE>-15V.
Absolute accuracy is a measure of each output current level with
respect to its intended value. It is dependent upon relative accuracy
and full-scale current drift. Relative accuracy, or linearity, is the
measure of each output current with respect to its intended fraction
of the full-scale current. The relative accuracy of the NE5410 is fairly
constant over temperature due to the excellent temperature tracking,
of the implanted resistors. The full-scale current from the reference
amplifier may drift with temperature causing a change in the
absolute accuracy. However, the NE5410 has a low full-scale
current drift with temperature.
The SE5410 and the NE5410 are accurate to within ± LSB at 25°C
with a reference current of 2.0mA on Pin 16.
The NE5410 and SE5410 are guaranteed monotonic over
temperature. This means that for every increase in the input digital
code, the output current either remains the same or increases but
never decreases. In the multiplying mode, where reference input
current will vary, monotonicity can be assured if the reference input
current remains above 0.5mA.
The worst-case switching condition occurs when all bits are
switched “on,” which corresponds to a LOW-to-HIGH transition for
all bits. This time is typically 250ns for the output to settle to within ±
1/2LSB for 10-bit accuracy, and 200ns for 8-bit accuracy. The
turn-off time is typically 120ns. These times apply when the output
swing is limited to a small (<0.7V) swing and the external output
capacitance is under 25pF.
The major carry (MSB off-to-on, all others on-to-off) settles in
approximately the same time as when all bits are switched off-to-on.
If a load resistor of 625Ω is connected to ground, allowing the output
to swing to -2.5V, the settling time increases to 1.5µs.
Extra care must be taken in board layout as this is usually the
dominant factor in satisfactory test results when measuring settling
time. Short leads, 100µF supply bypassing, and minimum scope
lead length are all necessary.
A typical test setup for measuring settling time is shown in Figure 7.
The same setup for the most part can be used to measure the slew
rate of the reference amplifier (Figure 9) by tying all data bits high,
pulsing the voltage reference input between 0 and 2V, and using a
500Ω load resistor RL.
August 31, 1994
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