PCA9634PW NXP Semiconductors, PCA9634PW Datasheet - Page 25

• Manufacturer Part Number: PCA9634PW
• Description: IC, LED DRIVER, RGBA, 20-TSSOP
• Manufacturer: NXP Semiconductors

Specifications of PCA9634PW

• No. Of Outputs: 8
• Output Current: 25mA
• Output Voltage: 5.5V
• Input Voltage: 2.3V To 5.5V
• Dimming Control Type: PWM
• Driver Case Style: TSSOP
• Switching Frequency: 1MHz
• Base Number: 9634
• Operating: RoHS Compliant
• Number Of Segments: 16
• Low Level Output Current: 200 mA
• High Level Output Current: 50 uA
• Operating Supply Voltage: 2.3 V to 5.5 V
• Maximum Supply Current: 10 mA
• Maximum Power Dissipation: 400 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-20
• Minimum Operating Temperature: - 40 C
• Led Driver Application: RGB Or RGBA LED Drivers, LED Status Information, Displays, Backlights
• Rohs Compliant: Yes
• Lead Free Status / Rohs Status: Details

NXP Semiconductors
11. Limiting values
PCA9634_6
Product data sheet
Question 3: Can I really sink 400 mA through the single ground pin on the package and
will this cause any ground bounce problem due to the PWM of the LEDs?
Question 4: I can’t turn the LEDs on or off, but their registers are set properly. Why?
Question 5: I’m using LEDs with integrated Zener diodes and the IC is getting very hot.
Why?
Table 16.
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
Yes, you can sink 400 mA through a single ground pin on the package. Although the
package only has one ground pin, there are two ground pads on the die itself
connected to this one pin. Although some ground bounce is likely, it will not disrupt the
operation of the part and would be reduced by the external decoupling capacitance.
Check the Mode Register 1 bit 4 SLEEP setting. The value needs to be 0 so that the
OSC is turn on. If the OSC is turned off, the LEDs cannot be turned on or off and also
can’t be dimmed or blinked.
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.
Parameter
supply voltage
voltage on an input/output pin
output current on pin LEDn
ground supply current
total power dissipation
storage temperature
ambient temperature
Limiting values
Rev. 06 — 12 September 2008
Conditions
operating
8-bit Fm+ I
Min
V
-
-
-
0.5
65
40
SS
0.5
PCA9634
2
© NXP B.V. 2008. All rights reserved.
C-bus LED driver
Max
+6.0
5.5
25
200
400
+150
+85
25 of 38
Unit
V
V
mA
mA
mW
C
C