FAN5702UC08X Fairchild Semiconductor, FAN5702UC08X Datasheet - Page 11

• Manufacturer Part Number: FAN5702UC08X
• Description: IC LED DVR 6LED 8MA I2C 16WLCSP
• Manufacturer: Fairchild Semiconductor
• Type: Backlight, White LED (I²C Interface)r

Specifications of FAN5702UC08X

• Topology: PWM, Switched Capacitor (Charge Pump)
• Number Of Outputs: 6
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Frequency: 900kHz ~ 1.5MHz
• Voltage - Supply: 2.7 V ~ 5.5 V
• Voltage - Output: 2 V ~ 4 V
• Mounting Type: Surface Mount
• Package / Case: 16-WLCSP
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 8mA
• Internal Switch(s): Yes
• Efficiency: 92%
• High Level Output Current: 180 mA
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Supply Current: 4.4 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: FAN5702UC08XTR

© 2010 Fairchild Semiconductor Corporation
FAN5702 • Rev. 1.0.3
Circuit Description
The FAN5702 is a white LED driver system based on an
adaptive 1.5x charge pump capable of supplying up to 180mA
of total output current. The tightly matched current sinks
ensure uniform brightness between the LEDs. Each LED has
a common anode configuration with its peak drive current set
during manufacturing (see Ordering Information and I
I
the individual current sinks as well as configure the grouping.
Each LED is controlled with 64 exponentially spaced analog
brightness control levels through I
For maximum flexibility, the FAN5702 can be programmed
with five independently controlled LED banks; by default,
arranged as 2,1,1,1,1 (first two LEDs represent Group A).
Through I
LEDs to Group A as needed by application requirements.
Charge Pump
The charge pump operates in either 1x mode, where V
connected to V
The circuit operates in 1x mode until the LED with the highest
forward voltage (V
regulation. At that point, 1.5x mode begins. If the lowest active
cathode voltage is greater than 1.8V, the charge pump
switches back to 1x mode.
IC Enable
By default the General Purpose register bit 7 = 0, the EN pin
functions as enable/disable. When the EN pin is LOW, all
circuit functions, including I
are set to their default values.
When the EN pin HIGH, I
can be turned on/off by writing to the General Purpose
register. The user can always communicate via I
device to change register settings regardless of whether any
LED is on or off.
PWM Dimming
By programming the General Purpose register bit 7 = 1, the
EN pin is reappropriated to a PWM dimming input. Applying a
PWM signal to this pin controls the LED current waveform to
be ON when the PWM dimming pin is HIGH and OFF when
the PWM dimming pin is LOW. By using this pin in conjunction
with the I
dimming resolution. For instance, an 8-bit PWM dimming
signal applied along with the 6-bit register dimming yields
better than 14 bits of resolution
To change the PWM dimming pin back to the EN function, set
the General Purpose register bit 7 to 0.
2
C-compatible interface is used to vary the brightness within
2
2
C, the device can be reconfigured to add up to six
C register dimming, the part can achieve higher
IN
through a bypass switch, or in 1.5x mode.
LED(MAX)
) can no longer maintain current
2
2
C interface is enabled. The LEDs
C, are disabled and the registers
2
C, as indicated in Table 1.
2
C with the
SET
OUT
). An
is
11
Register Controlled Brightness
The DC value of the LED current is modulated according to
the values in Table 1. Current is expressed as a percentage of
the full scale current and is illustrated with a 20mA I
Table 1. Brightness Control
Dimming Code (Bx5-Bx0)
000000
000001
000010
000011
000100
000101
000110
000111
001000
001001
001010
001011
001100
001101
001110
001111
010000
010001
010010
010011
010100
010101
010110
010111
011000
011001
011010
011011
011100
011101
011110
011111
100000
100001
100010
100011
100100
100101
100110
100111
101000
101001
101010
101011
101100
101101
101110
101111
110000
110001
110010
110011
110100
110101
110110
110111
111000
111001
111010
111011
111100
111101
111110
111111
Current Level
100.000%
10.874%
12.005%
13.253%
14.618%
16.124%
17.881%
19.875%
22.121%
24.621%
27.376%
30.373%
33.623%
37.124%
40.873%
44.875%
49.124%
53.624%
58.375%
63.378%
68.625%
74.122%
79.874%
85.873%
92.373%
0.125%
0.188%
0.249%
0.312%
0.374%
0.438%
0.499%
0.560%
0.622%
0.692%
0.750%
0.810%
0.875%
0.938%
1.004%
1.124%
1.250%
1.375%
1.499%
1.625%
1.750%
1.881%
2.063%
2.249%
2.438%
2.687%
2.939%
3.186%
3.562%
3.936%
4.310%
4.813%
5.314%
5.936%
6.565%
7.313%
8.059%
8.938%
9.876%
I
LED
www.fairchildsemi.com
(mA) (I
10.725
11.675
12.675
13.725
14.825
15.975
17.175
18.475
20.000
0.025
0.038
0.050
0.063
0.075
0.088
0.100
0.113
0.125
0.138
0.150
0.163
0.175
0.188
0.200
0.225
0.250
0.275
0.300
0.325
0.350
0.375
0.413
0.450
0.488
0.538
0.588
0.638
0.713
0.788
0.863
0.963
1.063
1.188
1.313
1.463
1.613
1.788
1.975
2.175
2.400
2.650
2.925
3.225
3.575
3.975
4.425
4.925
5.475
6.075
6.725
7.425
8.175
8.975
9.825
SET
SET
=20mA)
.