BL8095

BL8095
24V/1.2A Asynchronous Buck Converter in SOT23-6
DESCRIPTION
FEATURES











The BL8095 is a high efficiency current-mode
asynchronous, 24V/1.2A buck converter. Its input
voltage ranges from 4V to 24V and it provides an
adjustable regulated output voltage from 0.810V
to 5.5V while delivering up to 1.2A of output
current.
The switching frequency is set to 1.4MHz, which
works with a inductor as small as 4.7uH. And the
BL8095 will automatically switch between PFM
and PWM mode based on the load current, thus
to enhance the converter efficiency at light load.
APPLICATIONS
BL8095 consists of many protection blocks such
as UVLO, input voltage over voltage protection to
stand much higher input voltage spike, thermal
protection and output short circuit protection.





The BL8095 is available in the tiny SOT23-6
package.
TYPICAL APPLICATION and PIN OUT
10nF
VIN
5
SW
VOUT
5V/1.2A
4.7μH
6
LC2325
BL8095
25V
10μF
4
82K
EN
FB
GND
3
6.3V
22μF
16K
2
SW
VIN
EN
6
5
4
HBYW
1
2
3
BST
GND
FB
YW: Date code,
Year and Week
being assembled
SOT23-6
www.belling.com.cn
Security Camera
Consumer Electronic Device for automobile
Portable DVD
ADSL Modem, WLAN router
Other 12V or double cell Li-ion battery
powered device
LOW CURRENT CONSUMPTION
BST 1
VIN 12V
Adjustable Output Voltage, Vfb=0.810V
Output current is up to 1.2A
Range of operation input voltage: 4-24V
Input voltage UVLO: 3.7V (voltage decreasing)
Input Overvoltage Protection @26V
Withstand input voltage spike >30V
Operating current at zero load: 0.8mA (typ.)
Line regulation: 0.1%/V (typ.)
Load regulation: 10mV (typ.)
High efficiency, up to 90%
Environment Temperature: -20C~85C
1
BL8095
MARK and ORDERING INFORMATION
Mark Explanation
SW
VIN
EN
6
5
4
Ordering Information
HBYW
HB: Product Code
YW: Date code
1
2
3
BST
GND
FB
Product ID
BL8095CB6TR
Devices per reel
3000
SOT23-6
PINOUT DESCRIPTION
PIN #
1
2
3
NAME
BST
GND
FB
4
EN
5
6
VIN
SW
DESCRIPTION
High side power transistor gate drive boost input
Ground.
Feedback input with reference voltage set to 0.810V
Enable input. Setting it to high level or connecting to Vin via a resistor may turn on the chip,
while setting it to ground level will turn off the chip.
Power input, the input capacitor should be placed as close to VIN and GND pin as possible
Power switching node to connect inductor
BLOCK DIAGRAM
EN
BST
VIN
+
UVLO &
Thermal
shutdown
REG
&REF
Current
Sense
-
+
EA
+
COMP
network
Σ
-
FB
PWM
Logic
OSC
Slope Comp
GND
www.belling.com.cn
2
DRIVER
SW
BL8095
ABSOLUTE MAXIMUM RATING
Parameter
Value
Max Input Voltage
Max Operating Junction Temperature(Tj)
Ambient Temperature(Ta)
SOT23-6 (JC)
Package Thermal Resistance
SOT23-6 (JA)
Storage Temperature(Ts)
Lead Temperature & Time
ESD (HBM)
30V
125C
-20C – 85C
110C / W
220C / W
-40C - 150C
260C, 10S
>2000V
Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect
device reliability.
RECOMMENDED WORK CONDITIONS
Parameter
Value
Input Voltage Range
Output Voltage Range
Operating Junction Temperature(Tj)
4V - 24V
0.81 – 5.5V
-20C –125C
ELECTRICAL CHARACTERISTICS
(VIN=12V, TA=25C)
Symbol
Parameter
VDD
Input Voltage Range
VOUT
Output Voltage Range
Conditions
0.81
Feedback Voltage
Vin=12V, Ven=5V
VUVLO
UVLO Voltage
Vin H-->L, Iout=0.5A
Iq
0.790
0.810
Max
Unit
24
V
5.5
V
0.830
V
3.7
Feedback Leakage current
Quiescent Current
Typ
4
Vref
Ifb
Min
Active, Vfb=1V, No Switching
Shutdown, Vin=8V
V
0.1
0.4
uA
0.6
1.0
mA
6
10
uA
LnReg
Line Regulation
Vin=5V to 12V
0.1
%/V
LdReg
Load Regulation
Iout=0.1 to 1.2A
0.02
%/A
Switching Frequency
Ven=3V, Vin=12V
Fsoc
RdsonH
High side Switch Rdson
Isw=200mA
Ilimit
Peak Inductor Current Limit
Vin=12V, Vout=5V
Venh
EN High Threshold
1.0
1.4
1.8
MHz
250
350
mohm
1.5
2
1
1.5
A
3
V
0.5
V
Venl
EN Low Threshold
Vovp
Input Over-Voltage Protection
Ven=3V
26
V
TSD
Over Temperature Proection
Hystersis=40C
150
C
www.belling.com.cn
3
BL8095
TYPICAL PERFORMANCE CHARACTERISTICS
(Vin=12V, Vout=5.0V, L=4.7uH, Cin=10uF, Cout=22uF, TA=25C, unless otherwise stated)
Switching waveform Vin=12V, Iout=0.5A
Switching waveform Vin=12V, Iout=1A
(CH1=Vin, CH2=Vout, CH3=SW, CH4=Isw)
(CH1=Vin, CH2=Vout, CH3=SW, CH4=Isw)
www.belling.com.cn
4
BL8095
Switching waveform Vin=24V, Iout=0.5A
Switching waveform Vin=24V, Iout=1A
(CH1=Vin, CH2=Vout, CH3=SW, CH4=Isw)
(CH1=Vin, CH2=Vout, CH3=SW, CH4=Isw)
Load Transient Response
Load Transient Response
Vin=12V, Iout=0.12 - 1A
Vin=24V, Iout=0.12 - 1A
(CH1=Vin, CH2=Vout, CH4=Isw)
(CH1=Vin, CH2=Vout, CH4=Isw)
FUNCTIONAL DECRIPTIONS
Loop Operation
The BL8095 is a wide input range, high-efficiency, DC-to-DC step-down switching regulator, capable of delivering up to
1.2A of output current, integrated with a 250m MOSFET, with external schottky diode. It uses a PWM current-mode
control scheme. An error amplifier integrates error between the FB signal and the internal reference voltage. The output
of the integrator is then compared to the sum of a current-sense signal and the slope compensation ramp. This
operation generates a PWM signal that modulates the duty cycle of the power MOSFETs to achieve regulation for output
voltage.
Current Limit
There is a cycle-by-cycle current limit on the high-side MOSFET of 1.5A(typ). When the current flowing out of SW
exceeds this limit, the high-side MOSFET turns off and the external schottky diode rectifier turns on. Unlike the
traditional method of current limiting by limiting the voltage at the internal compensation node, which usually has large
variation due to duty cycle variance, this type of peak current limiting scheme provides a relatively more accurate limit
for output current, thereby lowering the requirements for system design.
Light Load Operation
Traditionally, a fixed current mode constant frequency PWM DC-DC regulator always switches even when the output
load is small. When energy is shuffling back and forth through the power MOSFETs, power is lost due to the finite
www.belling.com.cn
5
BL8095
RDSONs of the MOSFETs and parasitic capacitances. At light load, this loss is prominent and efficiency is therefore very
low. BL8095 employs a proprietary control scheme that improves efficiency in this situation by enabling the device into a
power save mode during light load, thereby extending the range of high efficiency operation.
COMPONENT SELECTRION
When setting up the BL8095 for different output voltage, please use following recommended component value for the
best performance.
VOUT (V)
5
3.3
2.5
COUT (F)
22
22
22
L (H)
6.8 - 10
4.7 - 10
3.3 - 10
THERMAL CONSIDERATION
BL8095 is high efficiency Buck converter, which means it consumes very few power when converting the high voltage to
low voltage. However, when output power is very large, like 5V/1.2A, the output power is as high as 6W, a heat
dissipation path is strongly recommended to be routed on PCB. BL8095 is in SOT23-6 package. The heat is conducted out
via Pin 2 (GND), so the heat dissipation route on PCB should be connected to the Pin 2 of the chip.
PACKAGE OUTLINE
Package
SOT23-6
Devices per reel
Package specification：
www.belling.com.cn
6
3000
Unit
mm