Document
LD8105
5/29/2012
Constant Voltage and Constant Current Controller
Rev. 00
General Description
The LD8105 is built-in with a high-accuracy 1.2V voltage reference, two op-amps and a low-side current sensing circuit in a SOT-26 package. It provides a highly integrated solution for CV (constant voltage) and CC (constant current) dual control. The LD8105 is capable to operate under temperature ranging from -40°C to 105°C.
Features
Internal Precision ±1% Voltage Reference Secondary-side Constant Voltage and Constant
Current Control Low Quiescent consumption Wide VCC operating range 3V to 38V Max. 40V voltage rating Low external component count SOT-26 Package
Applications
LED Lighting
Typical Application
IREF 1.21V
VCC
OUT
100mV
ISEN
LD8105
GND
VSEN
Fig. 1 Typical Application Circuit -1
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DC output
LD8105
VCC
IREF
1.21V
OUT
ISEN 100mV LD8105
GND
VSEN
Fig. 2 Typical Application Circuit -2
DC output
Pin Configuration
SOT-26 (TOP VIEW) VCC OUT IREF
65 05
YWV pp 12
4 3
Y: W: PP : V05 :
Year code (D: 2004, E: 2005…..) Week code Production code LD8105
ISEN GND VSEN
Ordering Information
Part number
Package
LD8105GL
SOT-26
The LD8105 is Green Packaged.
TOP MARK YWV/05
Shipping 3000 /tape & reel
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Pin Descriptions
LD8105
PIN NAME
FUNCTION
1 ISEN Current sense pin. The inverting input of the current loop op amp.
2 GND Ground. Voltage sense pin. It can sense the output voltage if connected to the mid-point
3 VSEN of the resistor divider.
4 IREF The non-inverting input of the current loop op amp.
5 OUT Common output pin of the two internal op amps.
Supply voltage pin. It is necessary to locate a 0.1F bypass capacitor between 6 VCC
VCC and GND.
Block Diagram
IREF
1.21V
VCC
OUT
ISEN
100mV
GND
VSEN
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Absolute Maximum Ratings
Supply Voltage, Vcc VSEN ISEN IREF OUT Maximum sink current Maximum Junction Temperature Operating Junction Temperature Operating Ambient Temperature Storage Temperature Range Package Thermal Resistance Power Dissipation (At Ambient Temperature = 85C) Lead temperature (Soldering, 10sec) ESD Voltage Protection, Human Body Model ESD Voltage Protection, Machine Model
LD8105
-0.3 ~40V -0.3~6V -0.3~6V -0.6~6V -0.3~Vcc 20mA 125C -40C to 125C -40C to 85C -65C to 150C 250C/W 160mW 260C 2 KV 200 V
Caution: Stresses beyond the ratings specified in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Recommended Operating Conditions
Item Supply Voltage Vcc
Min. 3
Max. 38
Unit V
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Electrical Characteristics
(TA = +25C unless otherwise stated, VCC=15.0V)
PARAMETER
CONDITIONS
Supply Voltage (Vcc Pin)
Supply Voltage
Quiescent Current
ISEN = IREF = 0V, OUT = open
Voltage Control Loop (VSEN PIN)
Voltage loop reference voltage, VSEN
Voltage Loop Input Bias Current Current Control Loop (IREF Pin)
ISEN = IREF = 0V ISEN = IREF= 0V, (TA = -20C ~125C) VSEN = 1.18V~1.24V
Current loop reference voltage, IREF Current Loop Input Bias Current Output (Output Pin)
VSEN = 1.21V IREF= 90mV~110mV
Output Low Level
@2mA sink current
LD8105
MIN TYP MAX UNITS
3 -- 38 V -- -- 150 μA
1.198 1.186
--
1.210 ---
1.222 1.234
20
V V nA
97 100 103 mV -- -- 20 nA
-- 200 400 mV
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Typical Performance Characteristics
96 Vcc=15V
91 Vcc=3V
86
81
121 105 89 73
LD8105
Vcc=3V Vcc=15V
Low Output Voltage Level (V)
Quiescent Current (A)
76 -40
-20 0
20 60
80 80 100 120
Temperature (C)
Fig. 1 Quiescent Current vs. Temperature
1.23
1.22
Vcc=3V Vcc=15V
1.21
57 -40
-20
0
20 60
80 80 100 120
Temperature (C)
Fig. 2 Low Output Voltage Level vs. Temperature
103
102
Vcc=3V Vcc=15V
101
Current Loop Reference (mV)
Voltage Loop Reference (V)
1.20
100
1.19-40
-20
Fig. 3
0
20 60
80 80 100 120
Temperature (C)
Voltage Loop Reference vs. Temperature
99 -40
-20
Fig. 4
0
20 60
80 80 100 120
Temperature (C)
Current Loop Reference vs. Temperature
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Package Information
SOT-26
LD8105
Symbol
A B C D F H I J M θ
Dimension in Millimeters
Min Max
2.692
3.099
1.397
1.803
-------
1.450
0.300
0.500
0.95 BSC.
0.080
0.254
0.050
0.150
2.600
3.000
0.300
0.600
0° 10°
Dimensions in Inches
Min Max
0.106
0.122
0.055
0.071
-------
0.057
0.012
0.020
0.003 0.002 0.102 0.012
0°
0.010 0.006 0.118 0.024
10°
Important Notice
Leadtrend Technology Corp. reserves the ri.