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MP1521
High Efficiency
White LED Driver
Absolute Maximum Ratings
Supply Voltage (V
IN
)
Switch Voltage to GND
V
EN
, V
REF
, V
BRT
, V
FB1
, V
FB2
, V
FB3
Storage Temperature
MP1521 Rev 2.7 10/06/04
www.monolithicpower.com
2
Monolithic Power Systems
28V
-0.5V to 28V
–0.3V to 6V
-55
°
C to +150
°
C
Recommended Operating Conditions
Supply Voltage (V
IN
)
Operating Temperature
Switch Voltage to GND
Package Thermal Characteristics
Thermal Resistance,
Θ
JA
(MSOP10)
Thermal Resistance,
Θ
JA
(QFN16)
2.7V to 25V
-20
°
C to +85
°
C
-0.5V to 25V
150°C/W
60°C/W
Electrical Characteristics
(V
IN
= 5.0V, T
A
= 25
°
C unless specified otherwise)
Parameters
Symbol
Supply Current (shutdown)
I
IN (OFF)
Supply Current (quiescent)
I
IN (ON)
Minimum Off Time, normal
operation
Minimum Off Time, start-up
(Note 1)
UVLO
Under Voltage Lockout
Enable
Threshold
Hysterisis
Leakage Current
Open Load Shutdown
Threshold
Condition
Min
Typ
1
550
Max
3
700
Units
μ
A
μ
A
V
EN
<0.4V
V
EN
>1.5V, V
BRT
=0V, V
FB
=0V
V
EN
>1.5V, V
BRT
=0.6V
V
FB
=0
V
EN
>1.5V, V
BRT
=0.6V,
V
FB
=0V
t
OFF (NORMAL)
400
500
700
nS
t
OFF (START)
1.5
2.4
μ
S
V
IN
RISING
V
IN FALLING
2.1
1.9
2.6
2.4
V
V
V
EN
=3V
0.8
1.0
60
2.0
1
V
mV
μ
A
Measured at OLS Pin
V
OLS
=15V
V
OLS
=25V
26
29
1
70
V
μ
A
μ
A
Leakage Current
45
Reference
Output Voltage
Load Regulation
Line Regulation
Feedback Comparator
Threshold
Hysterisis (Note 2)
FB Input Bias Current
PWM Mode
Output-Off Threshold
BRT Input Bias
BRT Full Scale Threshold
(Note 3)
Output Switch
Switch On Resistance (Note 2) R
ON
Switch Current Limit
Leakage Current
Thermal Shutdown (Note 2)
Notes:
1) First 64 pulses after EN switches high.
2) Guaranteed by design.
3) The output current is off when BRT is driven below the output-off threshold and full-scale when driven above the full-scale
threshold. To PWM the output drive BRT above and below these thresholds.
I
REF
=0A
I
REF
=0 to 100
μ
A
V
IN
=3 to 15V, I
REF
=0A
1.20
1.235 1.27
2.5
2.5
V
mV
mV
5
5
V
BRT
=1.2V
V
BRT
=1.2V
V
FB
=0.2V
380
-150
400
30
-50
420
0
mV
mV
nA
V
BRT
=0.6V
0.18
-100
0.26
0
V
nA
-30
1.2
V
V
IN
=5.0V
V
SW
=25V
0.5
400
160
0.6
5
mA
μ
A
°
C
300