Ap3156, Functional description – Diodes AP3156 User Manual
Page 10
AP3156
HIGH EFFICIENCY 1X/1.5X/2X CHARGE PUMP
FOR WHITE LED APPLICATIONS
AP3156 Rev. 1
10 of 15
SEPTEMBER 2009
©
Diodes Incorporated
Instruction & Data Table
First
Sequence
Second
Sequence
Description
1~3
- No
Action
4~7
1~32 Reserved
8
1
2
3
4~32
Switching frequency selected to
0.5MHz
Switching frequency selected to
1MHz (default)
Switching frequency selected to
2MHz
Reserved
9
1
2
3
4~32
20mA Constant Current Mode,
32 current level supported
(default)
Low Current Mode, 4 current level
supported
25mA Constant Current Mode,
32 current level supported
Reserved
10
1~32
*
Set current level for all 6
Channels
11
1~32
*
Set current level for CH1, CH2,
CH3
12
1~32
*
Set current level for CH4, CH5,
CH6
13
1~32
*
Set current level for CH1, CH2,
CH3, CH4
14
1~32
*
Set current level for CH5, CH6
15
1~32
*
Set current level for CH1, CH2,
CH3, CH4, CH5
16
1~32
*
Set current level for CH6
17 1~32
*
Set current level for CH5
18
1~32
*
Set current level for CH4
19
1~32
*
Set current level for CH3
20
1~32
*
Set current level for CH2
21
1~32
*
Set current level for CH1
22~32
-
Reserved
33
-
Soft Reset
1) 1MHz switching frequency
2) 20mA Constant Current Mode
3) All Channels in Current Level
Setting 32 (0mA)
34
-
Null Sequence
35~63
-
Reserved
*
Only 1~5 are valid current settings at Low Current Mode.
Disabled Current Sinks
Unused current channels must be disabled by connecting the
sinks to V
OUT
with only a small sense current flowing through
the disabled channel.
Soft-Start
Soft-start is incorporated to prevent excessive inrush current
during power-up, mode switching, and transitioning out of
stand-by mode.
Short-Circuit Protection
Short-circuit protection function is incorporated to prevent
excessive load current when either flying cap terminals or
output pin electrically tied to a very lower voltage or ground.
Over-Voltage Protection
Over-Voltage Protection function is incorporated to limit the
output voltage under a safe value to avoid on-chip device
breakdown.
Under-Voltage Lockout
Under-Voltage lockout feature disables the device when the
input voltage drops below UVLO threshold.
Thermal Auto Shutdown
When the die temperature exceeds the thermal limit, the
device will be disabled and enter stand-by mode. The
operation resumes whenever the die cools off sufficiently.
Switching frequency
By default, the AP3156 is working at 1MHz switching
frequency. It can also work at 0.5MHz or 2MHz switching
frequency which can be set through the Serial Digital Interface.
An user can choose the appropriate switching frequency with
consideration of noise immunity, input and output voltage
ripple requirement, and capacitor selection.
Functional Description
(Continued)