CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: T
J
= T
C
= T
A
Electrical Specifications
PARAMETER
V
IN
V
BAT
V
BATMAX
I
S
E
N
I
S
D
IS
R
SWITCH
V
DC
R
OUTOL
R
OUTCL
C
MIN
I
OUT
I
LIMBOOST
I
LIMBOOST
I
LIMFLASH
T
DELOV
OVPH
OVPL
V
HIGATE
V
FB
V
FLASH
V
LEVEL
F
SW
F
MOD
T
SWITCH
RLS
DRIVER
T
FAULT
T
FLASH
V
BAT
= V
IN
= 12V, V
DC
= 5V, I
OUT
= 350mA, T
A
= -40°C to +85°C unless otherwise specified.
CONDITIONS
Normal operating range
Normal operating range
If V
BAT
> V
BATFAULT
, FAULT pin is
switched to ground
No switching, EN/PWM = 1
No switching, EN/PWM = 0
I
SWITCH
= 1.2A
4.75
V
IN
< V
DC
V
IN
> 5V, F < 100Hz
0.1
4 LED output string
BOOST/BUCKN = VDC
BOOST/BUCKN = GND
TEMP = VDC
3.6
2.4
6
20
TBD
34
17
TBD
V
DC
0.2
0.4
GND
TBD
Mode = 1, modulation signal applied to
EN/PWM
C
GATE
= 2nF
100
25
TBD
Maximum flash timer period
TBD
50
16
TBD
TBD
TBD
1
3
TBD
600
1000
MIN
2.7
2.7
17.6
TBD
TBD
20
2
10
0.15
5
5.25
50
5
TYP
MAX
16
16
24.4
UNIT
V
V
V
mA
µA
Ω
V
Ω
Ω
µF
mA
A
A
A
ns
V
V
V
V
V
V
MHz
Hz
ns
Ω
ms
ms
DESCRIPTION
Input Supply Voltage
Input Supply Monitor
Supply Fault Threshold
Supply Current in V
IN
Supply Current in V
IN
Power FET On Resistance
Regulated Auxiliary Supply
Auxiliary Supply Open Loop Output
Resistance
Auxiliary Supply Closed Loop Output
Resistance
V
DC
Filter (Compensation) Capacitor
Output Drive Current
Power Switch Current Limit
Power Switch Current Limit
Power Switch Current Limit
Transition Delay from Current to Voltage LX fault protection activation
Mode
Over Voltage Positive Going Voltage
Mode Threshold
Over Voltage Negative Going Voltage
Mode Threshold
Switch Driver Supply
Feedback Voltage
Feedback Voltage in Flash Mode
Light Control Voltage Input Range
Switching Frequency
External Light Modulation Frequency
Load Switch Transition Time
Load Switch Driver Impedance
Fault Timer Period
Flash Timer Period
Upper threshold to enter overvoltage fault
mode
Lower threshold to exit overvoltage fault
mode
In buck mode (V
HI
- V
IN
),
In boost mode (V
HI
- GND)
System in regulation, V
LEVEL
= 1V
Independent of V
LEVEL
Mode = 1, analog control of LED current
2
FN7354.0
December 22, 2005
EL7801
Electrical Specifications
PARAMETER
T
DELAY
V
GATE
V
FAULTPUMP
VMODE
L
VMODE
H
en
FLASH
dis
FLASH
en
FAULT
dis
FAULT
en
TEMP
dis
TEMP
T
TRIP
VEN/PWM
L
VEN/PWM
H
.
V
BAT
= V
IN
= 12V, V
DC
= 5V, I
OUT
= 350mA, T
A
= -40°C to +85°C unless otherwise specified.
CONDITIONS
Timed LX switching delay
|V
FAULT
- V
IN
|
V
BAT
= V
IN
= 3V
V
DC
= 5V
V
DC
= 5V
2x
V
DC
/3
0.96V
DC
0.94V
DC
0.94V
DC
0.96V
DC
0.06V
DC
0.04V
DC
125
1.2
2.5
MIN
TBD
TBD
6
V
DC
/3
TYP
1
10
TBD
MAX
UNIT
ms
V
V
V
V
V
V
V
V
V
V
C
V
V
DESCRIPTION
Start-up Delay
External FET Gate Clamp
Fault Pin Charge Pump
Mode Pin Input Low Threshold
Mode Pin Input Low Threshold
Input Level Applied to TEMP Pin to Enter V
DC
= 5V
Flash Mode
Input Level Applied to TEMP Pin to Exit
Flash Mode
Input Level Applied to TMAX Pin to
Enable Fault Protection
Input Level Applied to TMAX Pin to
Disable Fault Protection
Input Level Applied to TEMP Pin to
Enable Temperature Compensation
Input Level Applied to TEMP Pin to
Disable Temperature Compensation
Internal Temperature Protection
Threshold
EN/PWM Pin Input Low Threshold
EN/PWM Pin Input High Threshold
V
DC
= 5V
V
DC
= 5V
V
DC
= 5V
V
DC
= 5V
V
DC
= 5V
TABLE 1. LIGHT OUTPUT CONTROL, V
DC
= 5.0V
MODE
1
Don’t Care
Don’t Care
0
TEMP
(V
DC
- 0.25V) > V > 0.25V
V > (V
DC
- 0.25V)
V < 0.25V
V < (V
DC
- 0.25V)
OPERATING MODE
Standard Mode
light level to PWM modulation of EN/PWM input; LED bias current
determined by LEVEL voltage, nominal 1V
Flash Mode,
internal current limit set to 6A; duration of flash set by ENABLE/PWM input;
T
ON
max limited internally to 25ms, V
FB
= 0.4V, independent of V
LEVEL
Disable temperature compensation
Fixed Bias Mode
V
FB
level internally set to 0.4V, independent of V
LEVEL
3
FN7354.0
December 22, 2005
EL7801
Typical Application Diagram
V
BAT
VIN
FAULT
VBAT
V
DC
0.1µF
TEMP
SENSOR
VDC
VHI
SWD1
SWD2
VOUT
BOOST/BUCKN
TEMP
TMAX
PWM
EN/PWM
MODE
LEVEL
1V
SWS1
SWS2
FB
ENL
GND
BOOST MODE
FIGURE 1. TYPICAL APPLICATION CIRCUIT
Pin Descriptions
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
NAME
VDC
VHI
V
OUT
SWD1
SWD2
DESCRIPTION
Internally regulated 5V supply, tracks V
IN
for input voltages less than 5V
Power FET gate drive supply
Overvoltage monitor input; tie to V
OUT
for normal operation
NMOS power FET drain
NMOS power FET drain
BOOST/BUCKN Digital input, configures controller to operate in BOOST or BUCK mode, low for BOOST, high for BUCK
LEVEL
TEMP
FB
TMAX
SWS2
SWS1
EN/PWM
MODE
ENL
VBAT
N/C
GND
FAULT
VIN
Sets LED bias current level; VFB(nominal) = VLEVEL/5
Temperature reference, tie to GND to disable temperature compensation, tie to VDC to enable camera flash
mode
LED current feedback
Maximum LED temperature set point; If TEMP voltage exceeds TMAX, FB set point is reduced
NMOS power FET source
NMOS power FET source
Chip enable, light modulation PWM input
Digital Input; tie to GND to set FB reference to 400mV, tie to VDC to control FB reference with LEVEL input
LED load isolation switch gate driver
Input supply monitor
Leave floating (internally connected)
Ground return and FB ground reference
Gate drive of fault FET. Driven low under fault conditions
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