TMC3003 Datasheet, PDF (5/12 Pages) Fairchild Semiconductor – Triple Video D/A Converter

PRODUCT SPECIFICATION
TMC3003
Pin Descriptions (continued)
Pin Number
Pin Name PLCC
LQFP
Voltage Reference
VREF
38
35
RREF
39
36
COMP
37
34
Power and Ground
VDD
18, 33, 34
GND
30, 31
12, 30, 31
27, 28
Value Description
+1.235 V
560 Ω
Voltage Reference output/input. An internal voltage
source of +1.235 Volts is output on this pin. An external
+1.235 Volt reference may be applied here which
overrides the internal reference. Decoupling VREF to GND
with a 0.1µF ceramic capacitor is required.
Current-setting resistor. The full-scale output current of
each D/A converter is determined by the value of the
resistor connected between RREF and GND. The nominal
value for RREF is found from:
RREF = 9.1( VREF/IFS)
where IFS is the full-scale (white) output current (in amps)
from the
D/A converter (without sync). Sync is 0.4 * IFS.
D/A full-scale (white) current may also be calculated from:
IFS = VFS/ RL
0.1 µF
Where VFS is the white voltage level and RL is the total
resistive load (in ohms) on each D/A converter. VFS is the
blank to full-scale voltage.
Compensation capacitor. A 0.1 µF ceramic capacitor
must be connected between COMP and VDD to stabilize
internal bias circuitry.
+5 V
0.0 V
Power supply
Ground
Equivalent Circuits
V_DD
p
Digital
Input
n
GND
27014C
Figure 2. Equivalent Digital Input Circuit
V_DD
n
p
V_DD
GND
OUT
27013B
Figure 3. Equivalent Analog Output Circuit
REV. 1.0.3 3/5/01
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