Datasheet

ADM8843
Rev. C | Page 11 of 16
Table 6. Digital Inputs Truth Table
CTRL1 CTRL2 LED Operation
0 0 Sub display off/main display off (full shutdown)
1, 2
0 1 Sub display off/main display on
1, 3
1 0 Sub display on/main display off
1, 2
1 1 Sub display on/main display on (full on)
1, 3
0 PWM Sub display off/digital PWM brightness control on main display
4, 5
PWM 0 Digital PWM brightness control on sub display/main display off
2, 4
1 PWM Sub display on/digital PWM brightness control on main display
1, 5
PWM 1 Digital PWM brightness control on sub display/main display on
5
PWM PWM Digital PWM brightness control on sub and main display
5
1
Sub display on means the display is on with the maximum brightness set by the R
SET
resistor. CTRL1 = 1 means a constant logic level (V
CC
) is applied to CTRL1.
2
Main display off means only the main display is off. CTRL2 = 0 means a constant logic level (GND) is applied to CTRL2.
3
Main display on means the display is on with the maximum brightness set by the R
SET
resistor. CTRL2 = 1 means a constant logic level (V
CC
) is applied to CTRL2.
4
Sub display off means only the sub display LEDs is off. CTRL1 = 0 means a constant logic level (GND) is applied to CTRL1.
5
PWM means a digital PWM signal is applied to the CTRL1 and/or the CTRL2 pin with a frequency from 100 Hz to 200 kHz.
LED CONFIG.
FULL ON
SUB AND MAIN 50%
DUTY CYCLE
MAIN AND SUB OFF
CTRL1
CTRL2
V
OUT
I
LED
(SUB)
I
LED
(MAIN)
SUB DISPLAY
BRIGHTNESS
MAIN DISPLAY
BRIGHTNESS
37ms >
t
CP
> 15ms
SHDN
SHDN
50%
50%
100%
100%
80%
t
CP
05050-020
MAIN 80% DUTY CYCLE,
SUB OFF
Figure 20. Application Timing