MAX16816 Datasheet, PDF (21/33 Pages) Maxim Integrated Products – Programmable Switch-Mode LED Driver with Analog-Controlled PWM Dimming

Programmable Switch-Mode LED Driver
with Analog-Controlled PWM Dimming
Digital Soft-Start Duration Register (SS)
The MAX16816 programmable soft-start feature allows
the load current to ramp up in a controlled manner, elimi-
nating output overshoot during startup. Soft-start begins
once the device is enabled and V_CC has exceeded the
5.5V (min) rising threshold voltage. Adjust the soft-start
duration by configuring the EEPROM. Enter ‘111’ to dis-
able the soft-start feature. See Table 6.
Oscillator Enable/Disable Register (RTOF)
The MAX16816 features a programmable accurate
RTSYNC oscillator and resistor synchronized to an
external clock. Set the EEPROM bit RTOF to ‘1’ to dis-
able the external sync mode, and the RTSYNC oscilla-
tor, and to use the fixed internal frequency of 125kHz
as the switching frequency. Set RTOF to ‘0’ to synchro-
nize with an external oscillator or to program the exter-
nal oscillator frequency with an external resistor, R_T.
See Table 7.
Slope Compensation Register (ESLP)
The MAX16816 uses an internally generated ramp to
stabilize the current loop when operating at duty cycles
above 50%. Set the compensating slope by adjusting
the peak ramp voltage through the on-chip EEPROM.
See Tables 8 and 9.
Table 6. Digital Soft-Start Duration
DURATION
(µs)
4096*
2048
1860
1024
768
512
256
No SS
*Factory default
EEPROM ADDRESS
36h
35h
34h
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Table 7. Oscillator Enable/Disable
RT OSCILLATOR
RT Oscillator Off
RT Oscillator On*
*Factory default
EEPROM ADDRESS
37h
1
0
Table 8. Slope Compensation with Clock
Generated by RT Oscillator
SLOPE
COMPENSATION
(mV/clock cycle)
0
20
40
60
80
100
120*
140
160
180
200
220
240
260
280
300
*Factory default
EEPROM ADDRESS
3Bh
3Ah
39h
38h
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
Table 9. Slope Compensation with
External Clock Applied to RTSYNC or RT
Oscillator Off
SLOPE
COMPENSATION
(mV/µs)
EEPROM ADDRESS
3Bh
3Ah
39h
38h
0
2
4
6
8
10
12*
14
16
18
20
22
24
26
28
30
*Factory default
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
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