LM3528TMEV National Semiconductor, LM3528TMEV Datasheet - Page 18

• Manufacturer Part Number: LM3528TMEV
• Description: BOARD EVAL FOR LM3528 12MCRSMD
• Manufacturer: National Semiconductor

Specifications of LM3528TMEV

• Current - Output / Channel: 20mA
• Outputs And Type: 2, Non-Isolated
• Voltage - Output: 21V
• Features: Dimmable, I²C Interface
• Voltage - Input: 2.5 ~ 5.5V
• Utilized Ic / Part: LM3528
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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REGISTER DESCRIPTIONS
There are 4, 8 bit registers within the LM3528 as detailed in Table 1.
TABLE 1. LM3528 Register Descriptions
GENERAL PURPOSE REGISTER (GP)
The General Purpose register has four functions. It controls
the on/off state of MAIN and SUB/FB, it selects between Uni-
son or Non-Unison mode, provides for control over the rate of
change of the LED current (see Brightness Rate of Change
TABLE 2. General Purpose Register Bit Function
General Purpose (GP)
Brightness Main (BMAIN)
Brightness Sub (BSUB)
HWEN/PGEN/GPIO Control (HPG)
General Purpose I/O Control (GPIO)
Pattern Register 0 (PGEN0)
Pattern Register 1 (PGEN1)
Pattern Register 2 (PGEN2)
Pattern Register 3 (PGEN3)
Bit
FIGURE 6. General Purpose Register Description
0
1
2
3
4
5
6
7
Don't Care
Register Name
RMP0
RMP1
Name
OLED
ENM
ENS
UNI
Enable MAIN. Writing a 1 to this bit enables the main current sink (MAIN).
Writing a 0 to this bit disables the main current sink and forces MAIN high
impedance.
Enable SUB/FB. Writing a 1 to this bit enables the secondary current sink (SUB/
FB). Writing a 0 to this bit disables the secondary current sink and forces SUB/
FB high impedance.
Unison Mode Select. Writing a 1 to this bit disables the BSUB register and
causes the contents of BMAIN to set the current in both the MAIN and SUB/
FB current sinks. Writing a 0 to this bit allows the current into MAIN and SUB/
FB to be independently controlled via the BMAIN and BSUB registers
respectively.
Brightness Rate of Change. Bits RMP0 and RMP1 set the rate of change of
the LED current into MAIN and SUB/FB in response to changes in the contents
of registers BMAIN and BSUB (see brightness rate of change description).
OLED = 0 places the LM3528 in White LED mode. In this mode both the MAIN
and SUB/FB current sinks are active. The boost converter ensures there is at
least 500mV at V
OLED = 1 places the LM3528 in OLED mode. In this mode the boost converter
regulates V
the MAIN current sink to maintain current regulation.
These are non-functional read only bits. They will always read back as a 1.
SUB/FB
MAIN
to 1.244V. V
and V
Hex Address
0x10
0xA0
0xB0
0x80
0x81
0x90
0x91
0x92
0x93
SUB/FB
MAIN
.
Function
is unregulated and must be > 400mV for
18
Description), and selects between White LED and OLED
mode. Figure 6 and Table 2 describes each bit available with-
in the General Purpose Register. Table 3 summarizes the
output state of the LM3528 for the different combinations of
General Purpose register settings.
Power -On-Value
0XF8
0xFC
0xC0
0xE0
0xE0
0x00
0x00
0x00
0x00
30020540
Power-On-Value
0
0
0
0
0
0
1