BD6155FVM-TR Rohm Semiconductor, BD6155FVM-TR Datasheet - Page 4

• Manufacturer Part Number: BD6155FVM-TR
• Description: IC LED DRIVER DC/DC CONV 8MSOP
• Manufacturer: Rohm Semiconductor

Specifications of BD6155FVM-TR

• Constant Current: Yes
• Topology: Switched Capacitor (Charge Pump)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Frequency: 120kHz
• Voltage - Supply: 2.9 V ~ 5.5 V
• Voltage - Output: 5.6V
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP
• Operating Temperature: -25°C ~ 75°C
• Current - Output / Channel: 80mA
• Internal Switch(s): *
• Efficiency: *
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Communication ICs
! ! ! ! Circuit operation
1) Charge pump driver
2) Fixed current driver
At current control set up voltage1 (Current1, 2=High) resistor value between LEDS-GND is set as 2.7Ω.
Charge pump is consisted capacitor pin (pin7), external schotky diodes and capacitors.
Output voltage at no loading is 2VBAT-2VF. (VF is as same as schotky’s VF )
Output voltage at loading is referred Fig2. As standard example, however it depends on external components.
LED driver fixed current is determined by resistor value between LEDS pin (pin4) and GND.
The above current is loaded to LED as fixied current.
• LED drive current fix example
Current control setup voltage 1 (Current 1=High Current 2=High)
Current control setup voltage 2 (Current 1=Low Current 2=High)
Current control setup voltage 3 (Current 1=High Current 2=Low)
Current control setup voltage 4 (Current 1=Low Current 2=Low)
The less RSENSE, the bigger fixed current for LED drive.
Resistors value should be determined with confirmation of charge pump loading characteristics (Fig.2) and LED's I-V characteristics.
VBAT
Shotky diodes
RB521-S30
C (Pin7)
205mV ÷ 2.7Ω = 75.9mA
1µF
1µF
Charge pump output
LED
CURRENT1
CURRENT2
(2 expressions)
+
−
LED (5Pin)
LEDS (4Pin)
RSENSE
LEDS pin voltage
LED
Fig.2 Charge pump loading characteristics
15
12
205.0
155.0
105.0
(mV)
55.0
9
6
3
0
0
(Typical operating characteristics)
20
OUTPUT LOAD :
RSENSE=2.7Ω RSENSE=5.1Ω
40
VBAT=5.5V
VBAT=3.6V
VBAT=2.9V
75.9
57.4
38.9
20.4
LED drive current (mA)
60
(mA)
BD6155FVM
80
100
40.2
30.4
20.6
10.8
4/7