PCA9632DP1 NXP [NXP Semiconductors], PCA9632DP1 Datasheet - Page 25

• Manufacturer Part Number: PCA9632DP1
• Description: 4-bit Fm+ I2C-bus low power LED driver
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
11. Limiting values
PCA9632_3
Product data sheet
Question 5: I’m using LEDs with integrated Zener diodes and the IC is getting very hot.
Why?
Table 17.
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
V
V
I
I
P
T
T
O(LEDn)
SS
•
stg
amb
DD
I/O
tot
The IC outputs can be set to either open-drain or push-pull and default to push-pull
outputs. In this application with the Zener diodes, they need to be set to open-drain
since in the push-pull architecture there is a low resistance path to ground through the
Zener and this is causing the IC to overheat. The PCA9632/33/34/35 ICs all power-up
in the push-pull output mode and with the logic state HIGH, so one of the first things
that need to be done is to set the outputs to open-drain.
Limiting values
Parameter
supply voltage
voltage on an input/output pin
output current on pin LEDn
ground supply current
total power dissipation
storage temperature
ambient temperature
Rev. 03 — 15 July 2008
Conditions
operating
4-bit Fm+ I
2
C-bus low power LED driver
Min
V
-
-
-
0.5
65
40
SS
0.5
PCA9632
© NXP B.V. 2008. All rights reserved.
Max
+6.0
5.5
25
100
400
+150
+85
Unit
V
V
mA
mA
mW
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C
C