PRODUCT SPECIFICATION
TMC3503
Pin Descriptions
(continued)
Pin
Name
R
REF
Pin Number
LQFP
36
PLCC
42
Value
590
Ω
Pin Function Description
Current-setting Resistor.
The full-scale output current of each
D/A converter is determined by the value of the resistor
connected between R
REF
and GND. The nominal value for
R
REF
is found from:
R
REF
= 9.1 (V
REF
/I
FS
)
where I
FS
is the full-scale (white) output current (amps) from the
D/A converter (without sync). Sync is 0.4 I
FS
.
D/A full-scale (white) current may also be calculated from:
I
FS
= V
FS
/R
L
Where V
FS
is the white voltage level and R
L
is the total resistive
load (ohms) on each D/A converter. V
FS
is the blank to full-scale
voltage.
COMP
34
40
0.1 µF
Compensation Capacitor.
A 0.1 µF ceramic capacitor must be
connected between COMP and V
DD
to stabilize internal bias
circuitry.
Power Supply.
Ground.
Power, Ground
V
DD
GND
12, 30, 31 17, 34–36
1, 14, 15,
27, 28, 38,
39, 48
13, 24, 25,
37
29–32
+5 V
0.0V
NC
—
—
No Connect
Equivalent Circuits
V
DD
V
DD
p
Digital
Input
n
OUT
GND
GND
27014D
27013B
n
V
DD
p
Figure 2. Equivalent Digital Input Circuit Figure 3. Equivalent Analog Output Circuit
REV. 1.02 11/24/99
5
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
