VIN (V)

2.5

3

3.5

4

4.5

5

5.5

50

55

60

65

70

75

80

85

90

95

100

D034

TA = -40qC

TA = +25qC

TA = +85qC

VIN (V)

2.5

3

3.5

4

4.5

5

5.5

50

55

60

65

70

75

80

85

90

95

100

D035

TA = -40qC

TA = +25qC

TA = +85qC

VIN (V)

2.5

3

3.5

4

4.5

5

5.5

60

64

68

72

76

80

84

88

92

96

100

D032

TA = -40qC

TA = +25qC

TA = +85qC

VIN (V)

2.5

3

3.5

4

4.5

5

5.5

50

55

60

65

70

75

80

85

90

95

100

D033

TA = -40qC

TA = +25qC

TA = +85qC

VIN (V)

2.5

3

3.5

4

4.5

5

5.5

60

64

68

72

76

80

84

88

92

96

100

D030

TA = -40qC

TA = +25qC

TA = +85qC

VIN (V)

2.5

3

3.5

4

4.5

5

5.5

60

64

68

72

76

80

84

88

92

96

100

D031

TA = -40qC

TA = +25qC

TA = +85qC

29

LM3644, LM3644TT

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SNVSA52E – AUGUST 2014 – REVISED SEPTEMBER 2016

Product Folder Links: LM3644 LM3644TT

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Copyright © 2014–2016, Texas Instruments Incorporated

Ambient temperature is 25°C, input voltage is 3.6 V, HWEN = VIN, CIN = 2 × 10 µF, COUT = 2 × 10 µF and L = 1 µH, unless

otherwise noted.

ILED = 1 A

ƒSW = 2 MHz

Flash

VLED = 3.32 V

Figure 46. LED Efficiency vs Input Voltage

ILED = 729 mA

ƒSW = 2 MHz

Flash

VLED = 3.18 V

Figure 47. LED Efficiency vs Input Voltage

ILED1 and LED2 = 729 mA

Flash

VLED = 3.18 V

ƒSW = 2 MHz

Figure 48. LED Efficiency vs Input Voltage

ILED = 179 mA

Torch

VLED = 2.83 V

ƒSW = 2 MHz

Figure 49. LED Efficiency vs Input Voltage

ILED = 179 mA

ƒSW = 4 MHz

VLED = 2.83 V

Torch

Figure 50. LED Efficiency vs Input Voltage

ILED1 and LED2 = 179 mA

ƒSW = 2 MHz

VLED = 2.83 V

Torch

Figure 51. LED Efficiency vs Input Voltage