EEPROM-Programmable, High-Voltage, 350mA

LED Drivers with LED Current Foldback

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15

Thermal Foldback Knee Point (TFK)

Register (0x03), MAX16806

The TFK register is a 4-bit register that sets the thermal

knee. Only the first 4 bits of the data byte program the

6). The MAX16806 initiates dimming once the differential

voltage between TFP/SCL and TFN/SDA drops below the

programmed thermal foldback knee. The factory-default

register value is 1.174V, which corresponds to the

MAX6613 thermal sensor output to +60°C.

Thermal Foldback Slope Gain Register

(0x04), MAX16806

Thermal Foldback Slope Gain register is a 2-bit register

that sets the gain after the thermal foldback knee. Only

the first 2 bits of the data byte program the Thermal

Foldback Slope Gain register. The remaining 6 bits are

is 4V/V.

THERMAL FOLDBACK

KNEE POINT (°C)

(MAX6613)

THERMAL FOLDBACK

KNEE POINT (mV)

BIT 3

BIT 2

BIT 1

BIT 0

HEX

60

1174

0

0

0

0

(0x00)

65

1118

0

0

0

1

(0x01)

70

1062

0

0

1

0

(0x02)

75

1006

0

0

1

1

(0x03)

80

950

0

1

0

0

(0x04)

85

894

0

1

0

1

(0x05)

90

838

0

1

1

0

(0x06)

96

782

0

1

1

1

(0x07)

101

726

1

0

0

0

(0x08)

106

670

1

0

0

1

(0x09)

111

615

1

0

1

0

(0x0A)

116

559

1

0

1

1

(0x0B)

121

503

1

1

0

0

(0x0C)

126

447

1

1

0

1

(0x0D)

131

391

1

1

1

0

(0x0E)

136

335

1

1

1

1

(0x0F)

THERMAL FOLDBACK

SLOPE GAIN (V/V)

BIT 1

BIT 0

HEX

16

0

0

(0x00)

12

0

1

(0x01)

8

1

0

(0x02)

4

1

1

(0x03)

Table 7. Thermal Foldback Slope Gain