PCA9952Q900 Datasheet, PDF (8/45 Pages) NXP Semiconductors – 16-channel Fm+ I2C-bus 57 mA constant current LED driver AEC-Q100 compliant

NXP Semiconductors
PCA9952/Q900; PCA9955/Q900
16-channel Fm+ I²C-bus 57 mA constant current LED driver, AEC-Q100
7. Functional description
Refer to Figure 1 “Block diagram of PCA9952/Q900, PCA9955/Q900”.
7.1 Device addresses
Following a START condition, the bus master must output the address of the slave it is
accessing.
For PCA9955/Q900 there are a maximum of 16 possible programmable addresses using
the 4 hardware address pins.
For PCA9952/Q900 there are a maximum of 8 possible programmable addresses using
the 3 hardware address pins.
7.1.1 Regular I²C-bus slave address
The I²C-bus slave address of the PCA9955/Q900 is shown in Figure 3. To conserve
power, no internal pull-up resistors are incorporated on the hardware selectable address
pins and they must be pulled HIGH or LOW externally. Figure 4 shows the I²C-bus slave
address of the PCA9952/Q900.
Remark: Reserved I²C-bus addresses must be used with caution since they can interfere
with:
• ‘reserved for future use’ I²C-bus addresses (0000 011, 1111 1XX)
• slave devices that use the 10-bit addressing scheme (1111 0XX)
• slave devices that are designed to respond to the General Call address (0000 000)
• High-speed mode (Hs-mode) master code (0000 1XX)
slave address
slave address
1 1 0 A3 A2 A1 A0 R/W
1 1 0 0 A2 A1 A0 R/W
fixed
hardware
selectable
002aae914
fixed
hardware
selectable
002aae915
Fig 3. PCA9955/Q900 slave address
Fig 4. PCA9952/Q900 slave address
The last bit of the address byte defines the operation to be performed. When set to logic 1
a read is selected, while a logic 0 selects a write operation.
7.1.2 LED All Call I²C-bus address
• Default power-up value (ALLCALLADR register): E0h or 1110 000X
• Programmable through I²C-bus (volatile programming)
• At power-up, LED All Call I²C-bus address is enabled. PCA9952/Q900,
PCA9955/Q900 sends an ACK when E0h (R/W = 0) or E1h (R/W = 1) is sent by the
master.
See Section 7.3.10 “ALLCALLADR, LED All Call I²C-bus address” for more detail.
PCA9952Q900_PCA9955Q900
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 1 — 26 April 2013
© NXP B.V. 2013. All rights reserved.
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