lm27965sqx-m National Semiconductor Corporation, lm27965sqx-m Datasheet - Page 9

• Manufacturer Part Number: lm27965sqx-m
• Description: Dual Display White Led Driver With I2c Compatible Brightness Control
• Manufacturer: National Semiconductor Corporation

lects the register to which the data will be written. The third
byte contains data to write to the selected register.
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The chip address for LM27965 is 0110110, or 36h. The chip
address for LM27965-M is 0111000, or 38h.
INTERNAL REGISTERS OF LM27965
2
Register
General Purpose
Register
Bank A Brightness
Control Register
Bank B Brightness
Control Register
Bank C Brightness
Control Register
C COMPATIBLE CHIP ADDRESS
FIGURE 5. General Purpose Register Description
FIGURE 4. Chip Address
Internal Hex
Address
10h
A0h
B0h
C0h
ack = acknowledge (SDIO pulled down by either master or slave)
id = chip address, 36h for LM27965 or 38h for LM27965-M
Power On Value
0010 0000
1110 0000
1110 0000
1111 1100
FIGURE 3. Write Cycle
w = write (SDIO = "0")
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r = read (SDIO = "1")
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Note: ENA: Enables DxA LED drivers (Main Display)
Internal Hex Address: 0xA0 (BankA), 0xB0 (BankB), 0xC0
Note: DxA4-DxA0: Sets Brightness for DxA pins (BankA). 11111=Fullscale
FIGURE 6. Brightness Control Register Description
ENB: Enables DxB LED drivers (Aux Lighting)
ENC: Enables D1C LED driver (Indicator Lighting)
EN5A: Enables D5A LED voltage sense
EN3B: Enables D3B LED driver and voltage sense
DxB4-DxB0: Sets Brightness for DxB pins (BankB). 11111=Fullscale
Bit7 to Bit 5: Not Used
DxC1-DxC0: Sets Brightness for DxC pin. 11 = Fullscale
Bit7 to Bit2:Not Used
Full-Scale Current set externally by the following equation:
I
Dxx
= 200 × 1.25V / R
Internal Hex Address: 10h
SET
(BankC)
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