MAX8520 MAXIM [Maxim Integrated Products], MAX8520 Datasheet - Page 8

• Manufacturer Part Number: MAX8520
• Description: Smallest TEC Power Drivers for Optical Modules
• Manufacturer: MAXIM [Maxim Integrated Products]

Smallest TEC Power Drivers for
Optical Modules
8
(V
DD
QFN
_______________________________________________________________________________________
T
T
TEC
A
= 5V, circuit of Figure 1, T
1
2
3
4
5
6
7
8
9
= +45°C
= +25°C
THERMAL STABILITY,
PIN
COOLING MODE
D1, D2, D3
4s/div
E1, E2
UCSP
C1
C2
B1
A1
A2
A3
A4
MAX8520/21 toc20
PGND1
MAXIN
MAXIP
NAME
SHDN
COMP
MAXV
A
ITEC
REF
LX1
= +25°C unless otherwise noted)
TEMPERATURE
0.001°C/div
Power Ground 1. Internal synchronous-rectifier ground connection. Connect all PGND
pins together at power ground plane.
Shutdown Control Input. Pull SHDN low to turn off PWM control and ITEC output.
TEC Current-Monitor Output. The ITEC output voltage is a function of the voltage across
the TEC current-sense resistor. V
Maximum Negative TEC Current. Connect MAXIN to REF to set default negative current
limit to -150mV/R
network from REF to GND. The current limit will then be equal to -(V
Maximum Positive TEC Current. Connect MAXIP to REF to set default positive current limit
to 150mV/R
Maximum Bipolar TEC Voltage. Connect MAXV to REF to set default maximum TEC
voltage to V
Inductor Connection. LX1 is high-impedance in shutdown.
Current-Control Loop Compensation. Refer to the Compensation Capacitor section.
<150pF.
(150mV/R
from REF to GND. The current limit will then be equal to (V
GND. The maximum TEC voltage is equal to 4 x V
1.50V Reference Output. Bypass REF to GND with a 0. 1µF ceramic capacitor.
Typical Operating Characteristics (continued)
T
T
SENSE
TEC
A
= +25°C
SENSE
DD
= +25°C
ROOM TEMPERATURE
. To lower this limit, connect MAXV to a resistor-divider network from REF to
THERMAL STABILITY,
).
SENSE
. To lower this current limit, connect MAXIP to a resistor divider network
4s/div
. To lower this current limit, connect MAXIN to a resistor divider
MAX8520/21 toc21
ITEC
= V
FUNCTION
REF
TEMPERATURE
0.001°C/div
+ 8 (V
MAXV
OS
- V
T
T
or V
TEC
A
= +5°C
CS
= +25°C
MAXIP
DD
). Keep capacitance on ITEC
THERMAL STABILITY,
, whichever is lower.
HEATING MODE
Pin Description
/V
REF
MAXIN
4s/div
) x (150mV/R
/V
REF
MAX8520/21 toc22
) x
SENSE
TEMPERATURE
0.001°C/div
).