MAX16816 Maxim Integrated Products, MAX16816 Datasheet - Page 21

• Manufacturer Part Number: MAX16816
• Description: Programmable Switch-Mode LED Driver
• Manufacturer: Maxim Integrated Products

Table 6. Digital Soft-Start Duration
Table 7. Oscillator Enable/Disable
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
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.
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
See Table 7.
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.
* Factory default
* Factory default
DURATION
RT OSCILLATOR
RT Oscillator On*
RT Oscillator Off
No SS
4096*
2048
1860
1024
(µs)
768
512
256
Oscillator Enable/Disable Register (RTOF)
Digital Soft-Start Duration Register (SS)
Slope Compensation Register (ESLP)
______________________________________________________________________________________
Programmable Switch-Mode LED Driver
with Analog-Controlled PWM Dimming
36h
0
0
0
0
1
1
1
1
EEPROM ADDRESS
EEPROM ADDRESS
CC
35h
has exceeded the
0
0
1
1
0
0
1
1
37h
1
0
34h
0
1
0
1
0
1
0
1
T
.
Table 8. Slope Compensation with Clock
Generated by RT Oscillator
Table 9. Slope Compensation with
External Clock Applied to RTSYNC or RT
Oscillator Off
* Factory default
* Factory default
COMPENSATION
COMPENSATION
(mV/clock cycle)
(mV/µs)
SLOPE
SLOPE
120*
100
140
160
180
200
220
240
260
280
300
12*
20
40
60
80
10
14
16
18
20
22
24
26
28
30
0
0
2
4
6
8
3Bh
3Bh
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
EEPROM ADDRESS
EEPROM ADDRESS
3Ah
3Ah
w w w . D a t a S h e e t 4 U . c o
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
39h
39h
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
38h
38h
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
21