AP8800
350mA LED STEP-DOWN CONVERTER
AP8800
Document number: DS31764 Rev. 5 - 2
3 of 11
March 2011 Diodes Incorporated
Absolute Maximum Ratings
Symbol
V
IN
VIN pin voltage
V
SET
Set voltage relative to V
IN
VSW
SW voltage
V
CTRL
CTRL pin input voltage
T
J
Maximum Junction Temperature
T
LEAD
Maximum Lead Temperature
T
ST
Storage Temperature Range
Parameter
Rating
-0.3~30
Unit
V
V
V
V
°C
°C
°C
V
IN
-5 ~ V
IN
+0.3
-0.3~30
-0.3 ~ 5
125
300
-55 to +125
Caution:
Recommended Operating Condition
s
Symbol
T
A
Ambient Temperature Range
Duty Cycle
Using Inductor
≥
100μH (Note 2)
V
ENH
CTRL input voltage to attain 100% LED current
V
ENL
CTRL input voltage below which device turns off
Note:
2. For most applications the LED current will be within 8% over the duty cycle range specified. Duty cycle accuracy is also dependent on propagation
delay. Smaller size inductors can be used but LED current accuracy may be greater than 8% at extremes of duty cycle. This is most noticeable at
low duty cycles (less than 0.1) or when the input voltage is high and only one LED is being driven.
Electrical Characteristics
(V
IN
= 12V, T
A
= 25
°
C, unless otherwise specified)
Symbol
Parameter
V
IN
Operating input voltage
I
OUT
Continuous switch current
(Note 3)
I
Q
Quiescient current
F
OSC
Switching frequency
V
THD
Internal current sense threshold voltage V
IN
-V
SET
V
REF
Internal reference voltage
SET
SET pin input current
V
SET
=V
IN
-0.1
R
DS
(on)
On-resistance of internal switch
I
SW_Leakage
Switch pin leakage current
SO-8 (Note 4)
MSOP-8 (Note 4)
DFN3030-10 (Note 4)
SO-8 (Note 4)
MSOP-8 (Note 4)
DFN3030-10 (Note 4)
The absolute maximum ratings are rated values exceeding which the product could suffer physical damage.
These values must therefore not be exceeded under any condition.
Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events.
Suitable ESD precautions should be taken when handling and transporting these devices.
Parameter
Min
-40
0.1
1.25
Max
85
0.95
0.2
Unit
oC
V
Conditions
Min
8.0
-
-
-
92
-
-
Typ.
-
-
20
0.25
100
1.25
1.3
1.7
-
92
120
46
60
98
32
Max
28
350
30
-
108
-
-
2.2
5
-
-
-
-
-
-
Unit
V
mA
μ
A
MHz
mV
V
μ
A
μ
A
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
-
-
-
-
-
-
-
θ
JA
Thermal resistance junction-to-ambient
θ
JC
Thermal resistance junction-to-case
Notes:
3. Refer to figure 5 for the device derating curve.
4. Test condition for SOP-8L, MSOP-8L and DFN3030-10: Device mounted on FR-4 PCB, 2”x2”, 2oz copper, minimum recommended pad layout on
top layer and thermal vias to bottom layer ground plane. For better thermal performance, larger copper pad for heat-sink is needed.