LM2794EVAL National Semiconductor, LM2794EVAL Datasheet - Page 3

• Manufacturer Part Number: LM2794EVAL
• Description: BOARD EVALUATION LM2794
• Manufacturer: National Semiconductor

Specifications of LM2794EVAL

• Current - Output / Channel: 80mA
• Outputs And Type: 4, Non-Isolated
• Voltage - Output: 4 V
• Features: Charge Pump
• Voltage - Input: 2.7 ~ 5.5V
• Utilized Ic / Part: LM2794
• Lead Free Status / RoHS Status: Not applicable / Not applicable

BRGT (LM2794/5)
(Values Highlighted in Boldface exceed Maximum curent
range of the device if all D1-D4 are in use).
Besides adjusting the BRGT pin to control the brightness of
the LEDs, SD pin can also be used to control the brightness
Components List for LM2791/2
Voltage on
BRGT (V)
Schottky Diode
TABLE 6. LED Current When Using BRGT Input
0.5
1.0
1.5
2.0
2.5
3.0
Component
White LEDs
0
C
Name
R
C
HOLD
U1
C1
SET
IN
101.88
15.16
30.69
46.21
61.73
77.26
92.78
124Ω
(D1-D4 are active)
Current through LED (mA)
White LEDs (TOPLED)
Surface Mount Device,
Surface Mount Device
500Ω
11.46
15.31
19.16
23.01
26.86
3.76
7.61
(Continued)
Through hold
LM2791/2
R
Type
X7R
X7R
X7R
SET
10.64
12.78
14.92
900Ω
2.09
4.23
6.37
8.51
1750Ω
1.07
2.17
3.27
4.37
5.47
6.57
7.67
C2012X7R1C105K, 16V
C2012X7R1C105K, 16V
C2012X7R1C105K, 16V
by the end users, +/-1%
Value to be determined
LWT67C/LWT673
LM2791/2LD-L
BAT-54 =4P
3
Value
by applying a PWM signal at the SD pin and varying the duty
cycle. A duty cycle of zero will turn off the device and a 50%
duty cycle waveform will produce an average current of
7.5mA if the intended LED(s) current is 15mA.
Shutdown (LM2791/2)
During normal operation, SD pin is connected to V
LM2792LD-H) or connected to ground (for LM2792LD-L). If
SD pin is used to control the brightness instead of the BRGT
pin, applying a PWM (Pulse Width Modulation) signal in the
range of 100Hz to 1KHz is recommended for best result. In
the case of the LM2792, connect BRGT to 3V before apply-
ing a PWM signal at SD or connect BRGT pin to GND if
LM2791 is used),
Shutdown (LM2794/5)
During normal operation, SD pin is connected to V
LM2794) or connected to ground (for LM2795). If SD pin is
used to control the brightness instead of the BRGT pin, a
PWM signal in the range of 100Hz to 1KHz is recommended.
uF
uF
uF
SOT23-3
LLP-10
0805
0805
0805
Size
National Semiconductor
Manufacturer
Fairchild
Osram
TDK
TDK
TDK
www.national.com
IN
IN
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