FAN5616 Datasheet, PDF (5/14 Pages) Fairchild Semiconductor – High-Efficiency, Constant-Current LED Driver with Adaptive Charge Pump

Electrical Characteristics
Unless otherwise noted, V_IN = 2.7V to 5.5V, I_LED = 2mA to 20mA, EN1 = EN2 = HIGH, T_A = -40°C to +85°C. Typical
values are at 25°C.
Parameter
Input Under-Voltage Lockout
I_LED/I_SET Ratio
I_LED/I_SET Ratio
I_LED/I_SET Ratio
Current Matching with Unmatched
LEDs (Note 1)
Reference Voltage for Current Set
Start Up time
Minimum Cathode Voltage
Quiescent Current
Shutdown Supply Current
Output Short Circuit Current
V_OUT Over-voltage Protection
V_IN at Mode Transition from 1x to 1.5x
V_IN at Mode Transition from 1.5x to 2x
Peak Efficiency (Note 2)
Oscillator Frequency
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
“EN1” Logic Input Low Voltage
“EN1” Logic Input High Voltage
“EN2” Logic Input Low Voltage
“EN2” Logic Input High Voltage
Conditions
V_IN falling
V_IN rising
V_IN = 3.6V, I_OUT = 15mA
I_LED = 2 to 20mA
EN1 = HIGH, EN2 = LOW
EN1 = LOW, EN2 = HIGH
2mA ≤ I_LED ≤ 15mA
2.8V ≤ LED V_F <4V
C_OUT = 1µF, V_IN = 3.6V,
I_LED = 15mA
I_LED = 15mA
V_IN = 5.5V, I_OUT = 5mA
EN1 = EN2 = Logic “L”
V_IN = 5.5V, V_OUT = 0V
LED V_f = 3.5V, I_LED = 3 x 20mA
LED V_f = 3.5V, I_LED = 3 x 20mA
V_IN = 3.75V, LED V_f = 3.4V,
I_LED = 18mA
Min Typ Max Unit
1.6
V
2.3
240
255
270
230
260
280
86
173
0.6
+3
%
588
600
612
mV
200
270
500
µS
170
250
mV
250
µA
0.1
1
µA
65
80
mA
6
V
3.9
V
2.9
V
90
%
0.8
1
1.2
MHz
150
°C
15
°C
0.4
V
1.6
V
0.4
V
1.6
V
Notes:
1. Current Matching refers to the absolute value of the difference in the current between the two LED branches.
( ₍ ) _{) Current Matching (%) ––}
I_LEDi – I_LEDj
x 100
, where i, j = 1, 2 or 3
I_LEDi + I_LEDj
2. Efficiency is expressed as a ratio between the electrical power into the LEDs and the total power consumed from
the input power supply.
Σ3
V_LEDi x I_LEDi
Efficiency ^––
i=1
V_IN x I_IN
Some competitors calculate the efficiency as a function of V_OUT instead of LED V_F. Their method does not account
for the power lost due to the cathode voltage not being equal to zero. This method allows them to provide an
“improved” efficiency up to 5%.
5
FAN5616 Rev. 1.0.0
www.fairchildsemi.com