Smallest TEC Power Drivers for
Optical Modules
Typical Operating Characteristics (continued)
(V
DD
= 5V, circuit of Figure 1, T = +25°C unless otherwise noted)
A
SWITCHING FREQUENCY vs. R
SWITCHING FREQUENCY CHANGE vs. V
REFERENCE VOLTAGE CHANGE vs. V
EXT
DD
DD
1100
1000
900
800
700
600
500
400
1200
1000
800
600
400
200
0
0.6
0.4
REF SOURCING 150µA
FREQ = 1MHz
0.2
0.0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
-1.4
V
= 5V
DD
FREQ = 500kHz
V
= 3.3V
DD
60
80
100
R
120
(kΩ)
140
160
3.0
3.5
4.0
4.5
(V)
5.0
5.5
3.0
3.5
4.0
4.5
(V)
5.0
5.5
V
V
DD
EXT
DD
REFERENCE VOLTAGE CHANGE
vs. LOAD CURRENT
REFERENCE VOLTAGE CHANGE
vs. TEMPERATURE
STARTUP AND SHUTDOWN WAVEFORMS
MAX8520/21 toc17
0
-2
5
4
REF SOURCING 150µA
V
SHDN
5V/div
0V
3
2
-4
I
DD
1
200mA/div
0mA
-6
0
-1
-2
-3
-4
-5
-8
I
TEC
500mA/div
0mA
-10
-12
0
0.2
0.4
0.6
0.8
1.0
200µs/div
-40 -20
0
20
40
60
80
LOAD CURRENT (mA)
TEMPERATURE (°C)
CTLI STEP RESPONSE
V
STEP RESPONSE
DD
MAX8520/21 toc18
MAX8520/21 toc19
V
CTLI
1V/div
V
DD
2V/div
1.5V
0V
1A
0A
I
TEC
10mA/div
I
TEC
1A/div
1ms
10ms/div
_______________________________________________________________________________________
7
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
