Four-Channel Backlight Driver with Dual LDOs
Electrical Characteristics
1
C
IN
= C
O1
= C
O2
= 2.2µF, C
1
= C
2
= 1.0µF, C
BP
= 0.1µF; T
A
= 25°C, unless otherwise noted. Typical values are
at T
A
= 25°C and V
IN
= 3.6V.
Symbol
Power Supply
V
IN
I
SHDN
Charge Pump
1X Mode, 3.0
≤
V
IN
≤
5.5,
Active, No Load Current
1.5X Mode, 3.0
≤
V
IN
≤
5.5,
Active, No Load Current
2X Mode, 3.0
≤
V
IN
≤
5.5,
Active, No Load Current
50µA Setting, 1X Mode
20mA Setting, T
A
= 25°C
1mA Setting, T
A
= 25°C
V
IN
- V
F
= 1.5V
1.0
3.0
5.0
18
0.9
50
20
1.0
0.5
150
100
1
140
15
0.3
50
75
500
500
1
75
µA
22
1.1
1.0
mA
%
mV
µs
MHz
°C
°C
µs
ns
µs
µs
µs
µA
mA
AAT2845
Description
Input Voltage
Total Shutdown Current at VIN
and LDOIN
Conditions
Min
2.7
Typ
Max Units
5.5
1.0
V
µA
EN/SET = ENLDO = GND
I
CC
Operating Current
I
DX
I
(D-Match)
Average Current Accuracy
Current Matching
2
1X to 1.5X or 1.5X to 2X Transition
V
TH
Threshold at Any DX Pin
T
SS
Soft-Start Time
F
CLK
Clock Frequency
Over-Temperature Shutdown
T
SD
Threshold
Over-Temperature Shutdown
T
HYS
Hysteresis
EN/SET Logic Control
T
EN/SET LO
EN/SET Low Time
T
EN/SET HI MIN
Minimum EN/SET High Time
T
EN/SET HI MAX
Maximum EN/SET High Time
T
OFF
EN/SET Off Timeout
T
LAT
EN/SET Latch Timeout
I
EN/SET
EN/SET Input Leakage
V
EN/SET
= V
IN
= 5V
-1
1. The AAT2845 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured
by design, characterization, and correlation with statistical process controls.
2. Current matching is defined as the deviation of any sink current from the average of all active channels.
4
2845.2006.12.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
