PCU9955TW,118 NXP Semiconductors, PCU9955TW,118 Datasheet - Page 19

• Manufacturer Part Number: PCU9955TW,118
• Description: LED Lighting Drivers 16-ch Ufm I2C-bus 57 mA LED driver
• Manufacturer: NXP Semiconductors

Specifications of PCU9955TW,118

• Rohs: yes
• Input Voltage: 3 V to 5.5 V
• Maximum Supply Current: 15 mA
• Mounting Style: SMD/SMT
• Package / Case: HTSSOP-28
• Power Dissipation: 3.2 W
• Factory Pack Quantity: 2500

NXP Semiconductors
PCU9955
Product data sheet
7.3.15 Overtemperature protection
7.4 Power-on reset
7.5 Hardware reset recovery
7.6 Software reset
If the PCU9955 chip temperature exceeds its limit (T
channels will be disabled until the temperature drops below its limit minus a small
hysteresis (T
T
event.
When power is applied to V
condition until V
PCU9955 registers and I
zeroes) causing all the channels to be deselected. Thereafter, V
than 1 V and stay LOW for longer than 20 s. The device will reset itself, and allow 2 ms
for the device to fully wake up.
When a reset of PCU9955 is activated using an active LOW input on the RESET pin, a
reset pulse width of 2.5 s minimum is required. The maximum wait time after RESET pin
is released is 1.5 ms.
The Software Reset Call (SWRST Call) allows all the devices in the I
the power-up state value through a specific formatted I
The maximum wait time after software reset is 1 ms.
The SWRST Call function is defined as the following:
1. A START command is sent by the I
2. The reserved General Call address ‘0000 000’ with the W bit set to ‘0’ (write) is sent
3. Since PCU9955 is a UFm I
4. Once the General Call address has been sent, the master sends 1 byte with 1 specific
5. Once the correct byte (SWRST data byte 1) has been sent, the master sends a STOP
th(otp)
by the I
master.
value (SWRST data byte 1): Byte 1 = 06h.
If more than 1 byte of data is sent, they will be ignored by the PCU9955.
command to end the SWRST function: the PCU9955 then resets to the default value
(power-up value) and is ready to be addressed again within the specified bus free
time (t
 T
hys
BUF
2
C-bus master.
, the chip will return to the same condition it was prior to the overtemperature
hys
).
, see
All information provided in this document is subject to legal disclaimers.
DD
has reached V
Table
Rev. 2 — 2 October 2012
2
16-channel UFm I
C-bus state machine are initialized to their default states (all
19). Once the die temperature reduces below the
DD
, an internal power-on reset holds the PCU9955 in a reset
2
C-bus device, no acknowledge is returned to the I
POR
. At this point, the reset condition is released and the
2
C-bus master.
2
C-bus 57 mA constant current LED driver
th(otp)
2
C-bus command.
, see
Table
DD
must be pulled lower
2
19), all output
C-bus to be reset to
PCU9955
© NXP B.V. 2012. All rights reserved.
2
C-bus
19 of 39