LM3528TMX National Semiconductor, LM3528TMX Datasheet - Page 19

• Manufacturer Part Number: LM3528TMX
• Description: LM3528 High Efficiency, Multi Display LED Driver with 128 Exponential Dimming Steps and Integrated OLED Power Supply in a 1.2mm - 1.6mm uSMD Package; Package: MICRO SMD; No of Pins: 12; Qty per Container: 3000; Container: Reel
• Manufacturer: National Semiconductor

TABLE 3. Operational Truth Table
* ENM ,ENS, or OLED high enables analog circuitry.
BRIGHTNESS REGISTERS (BMAIN and BSUB)
With the UNI bit (General Purpose register) set to 0 (Non-
Unison mode) both brightness registers (BMAIN and BSUB)
independently control the LED currents I
spectively. BMAIN and BSUB are both 8 bit, but with only the
7 LSB’s controlling the current. The MSB’s is a don’t care. The
LED current control is designed to approximate an exponen-
tially increasing response of the LED current vs increasing
code in either BMAIN or BSUB (see Figure 9). Program
I
where:
LED_MAX
UNI
X
X
X
1
1
0
0
0
by connecting a resistor (RSET) from SET to GND,
OLED
0
0
0
0
0
0
1
1
ENM
0
1
0
0
1
1
1
0
FIGURE 7. Brightness MAIN Register Description
FIGURE 8. Brightness SUB Register Description
MAIN
and I
ENS
SUB/FB
X
X
X
X
0
1
0
1
re-
SUB/FB current sink disabled (SUB/FB configured as a feedback
SUB/FB current sink disabled (SUB/FB configured as a feedback
MAIN and SUB/FB current sinks enabled. Current levels set by
MAIN and SUB/FB current sinks enabled. Current levels set by
19
pin). MAIN current sink enabled current level set by BMAIN.
SUB/FB current sink enabled. Current level set by BSUB.
MAIN current sink enabled. Current level set by BMAIN.
With the UNI bit (General Purpose register) set to 1 (Unison
mode), BSUB is disabled and BMAIN sets both I
FB
FB
cally 1%(with UNI = 0) to typically 0.15% (with UNI = 1). Figure
7 and Figure 8 show the register descriptions for the Bright-
ness MAIN and Brightness SUB registers. Table 4 and Figure
9 show I
age of I
. This prevents the independent control of I
, however matching between current sinks goes from typi-
contents of BMAIN and BSUB respectively.
LED_MAX
MAIN
pin). MAIN current sink disabled.
MAIN and SUB/FB Disabled
and/or I
.
contents of BMAIN.
LM3528 Disabled
SUB/FB
Result
vs. brightness data as a percent-
30020542
30020543
MAIN
MAIN
www.national.com
and I
and I
SUB/
SUB/