LD8115A [LEADTREND]
Secondary-side Dimmable Constant Current and Voltage Controller;
| 型号： | LD8115A |
| 厂家： | 
Leadtrend Technology |
| 描述： | Secondary-side Dimmable Constant Current and Voltage Controller |
| 文件： | 总12页 (文件大小：619K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LD8115A
08/02/2017
Secondary-side Dimmable Constant Current
and Voltage Controller
REV: 00
General Description
Features
Secondary-Side Constant Current and Voltage
The LD8115A is an isolation secondary LED constant
current and constant voltage controller, and provide the
secondary-side direct dimming interface by DC level and
PWM duty single for smart LED lighting application.
Feedback
High Accuracy 200mV (+/-2%) of LED Current
Threshold Control
Precision 1.25V Reference Voltage ( +/-1%)
Low operation current ( < 0.5mA)
Wide VCC Operation Range 3.6~38V
Precision Secondary-side LED current Dimming with
Analog and PWM
The device features include wide input voltage range from
3.6V to 38V, high-accuracy LED operation current and
output constant voltage.
-
-
Analog Dimming : 0.1V~2.5V
PWM: 500Hz~30kHz
Applications
The LD8115A is the SOP-8 package to minimize the PCB
size as well as component counts.
LED Lighting Driver Application
Charger
Typical Application
500Hz ~30KHz
PWM Duty
OUT
OUT
ADIM
ADIM
VCC
VSEN
ISEN
VCC
REF
VSEN
ISEN
LD8115A
LD8115A
REF
DCDIM
DCDIM
GND
GND
DC Level
0.25V~2.5V
Fig. 1 Application circuit-PWM Dimming
Fig. 2 Application circuit- Analog Dimming
1
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
LD8115A
08/02/2017
Pin Configuration
SOP-8
LD8115AGS
YYWWPP
YY:
WW:
PP:
Year Code
Week Code
Production Code
Ordering Information
Part number
Package
Top Mark
Shipping
LD8115A GS
SOP-8
Green package
LD8115AGS
2500 /tape & reel
The LD8115A is ROHS compliant/Green Packaged.
Protection Mode
Int. OTP
VCC OVP
Constant Current Loop Constant Voltage Loop
Auto recovery Auto recovery
Auto recovery
None
Pin Descriptions
Pin
NAME
FUNCTION
Power Supply to IC, a small bypass capacitor (0.1F) to GND and closed IC
as possible.
1
VCC
Ground. This pin should be tied as close to the ground output terminal of the
converter as possible to minimize load current effect on the voltage
regulation set point
Open-Collector Output .this pin is connected opto-coupler with the limit
resistor to error signal to the primary side.
Current sense pin. The inverting input of the current loop op amp. This pin is
tied to the end of the current sense resistor through a decoupling resistor
and the threshold voltage at maximum current is 200mV.
Voltage sense pin. Inverting input of the internal OP-amp. It connected to
the mid-point of a resistor divider that senses the output voltage.
In Analog dimming control, this pin is DC level signal input for brightness. If
the devise is PWM Dimming control, this pin adds a 0.1~1uF MLCC
capacitor to filtering PWM signal.
2
3
4
5
6
GND
OUT
ISEN
VSEN
DCDIM
Signal input for brightness control at PWM Dimming. When devise is in
7
8
ADIM
VREF
analog dimming mode, this pin connects to GND.
Internal linear regulator output pin with an external ceramic capacitor of
1~2.2F.
2
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LD8115A-DS-00 August 2017
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Block Diagram
VCC
VREF
Vref
All Block
internal bias
CV_Loop
OUT
VVSEN
1.25V
Negative edge Triggered
2.5V
RDIS.
VSEN
Hys.Circuit
Low: ≤0.5V
High: ≥2.6V
&
V
ISEN
CC_Loop
Dimming
Control
200mV
ADIM
RFILTER
Level Clamp
GND
DCDIM
ISEN
3
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
LD8115A
08/02/2017
Absolute Maximum Ratings
VCC
-0.3V ~ 40V
-0.3V ~ 60V
-0.3V ~ 16V
-0.3V ~ 6V
30mA
OUT
ADIM, DCDIM
VSEN, VREF, ISEN
OUT Maximum Sink Current
Maximum Junction Temperature
Storage Temperature Range
Package Thermal Resistance (SOP-8, JA)
Power Dissipation (SOP-8,at Ambient Temperature = 85C)
Lead temperature (Soldering, 10sec)
ESD Voltage Protection, Human Body Model
ESD Voltage Protection, Machine Model
150C
-65C to 150C
160C/W
250mW
260C
2KV
200V
Caution:
Stress exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stress above Recommended Operating Conditions may affect
device reliability.
Recommended Operating Conditions
Item
Min.
-40
Max.
125
38
Unit
C
Operating Junction Temperature
Supply VCC Voltage
3.6
V
Maximum LED Voltage
58
4.7
2.2
1
V
VCC pin capacitor
0.1
1
F
F
F
Hz
VREF pin capacitor
DCDIM pin capacitor @ Use PWM input to ADIM pin
ADIM Acceptable Frequency Range
0.1
500
30K
Note:
1. It’s essential to connect VCC pin with a SMD ceramic capacitor (0.1F~4.7F) to
filter out the undesired switching noise for stable operation. This capacitor should be
placed close to IC pin as possible
2. The small signal components should be placed close to IC pin as possible.
4
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LD8115A
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Electrical Characteristics
(VCC=15V, TA = 25C unless otherwise specified.)
PARAMETER
Supply Voltage (VCC Pin)
UVLO(OFF)
CONDITIONS
Symbol
MIN
TYP
MAX
UNITS
VCC_OFF
VCC_ON
2.5
2.8
2.7
3.0
2.9
3.2
V
V
UVLO(ON)
VISEN = VOVP
VDCDIM = 0V , OUT Pull
Low
=
5V,
Operation Current
IVCC
350
500
A
Gate Drive Output (OUT Pin)
@2mA sink current
Output Low Level
VOUTL
200
400
mV
Internal Reference Voltage(VREF Pin)
Reference Voltage
Good TC
VREF
3.04
3.2
3.36
10
V
IREF≤3mA
VREF Maximum Output
Current(1)
IREF
mA
DC Dimming (DCDIM Pin)
Maximum LED current
threshold at DIM pin(1)
Internal Filter Resistance(1)
VOVP = 0V,
VISEN =200mV+/-4mV
VDIM_MAX
RFILTER
2.6
V
1000
5
K
Internal Discharge
Resistance(1)
When VADIM is Changed
from 3V to 0V and
de-bounce TADM_OFF
RFILTER
K
PWM Dimming (ADIM Pin)
Dimming mode Selector
TADIM_OFF
ADIMH
ADIML
RADIM
20
60
ms
V
ADIM H/L Threshold Voltage
2.6
0.5
V
ADIM Input Resistor
300
600
K
DCDIM Discharge Resistor
When ADIM signal from high to
low and TADIM_OFF > 60ms
RDCDIS
5
K
Current Control Loop (ISEN PIN)
Maximum LED Current Sense
Threshold Voltage
VOVP = 0V, DCDIM =3.2V
VISEN
196
200
2
204
mV
VOVP = 0V,
When VDCDIM =0V
Or VADIM=0V
Minimum LED Current Sense
VISEN_0
ICC_BIAS
4
mV
nA
Reference Voltage
Current Loop Input Bias
Current (1)
20
5
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
LD8115A
08/02/2017
(VCC=15V, TA = 25C unless otherwise specified.)
PARAMETER
CONDITIONS
Symbol
MIN
TYP
MAX
UNITS
Voltage Control Loop (VSEN PIN)
Voltage Control Loop
VISEN = 0V
VVSEN
1.237
--
1.250 1.263
V
Threshold voltage
Voltage Loop Input Bias
Current(1)
ICV_BIAS
--
20
--
nA
Internal OTP
OTP Trip Level(1)
OTP Hysteresis(1)
135
30
C
C
--
Note: (1) Guarantee by Design
6
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LD8115A
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Typical Performance Characteristics
500.00
3.10
3.05
3.00
2.95
2.90
2.85
450.00
400.00
350.00
300.00
-40
0
40
80
120
-40
0
40
80
120
Temperature(℃)
Temperature(℃)
Fig. 3 IVCC vs. Temperature
Fig. 4 VCC_ON vs. Temperature
2.80
2.75
2.70
2.65
2.60
2.55
204
202
200
198
196
194
-40
0
40
80
120
-40
0
40
80
120
Temperature(℃)
Temperature(℃)
Fig. 5 VCC_OFF vs. Temperature
Fig. 6 VISEN vs. Temperature
3.30
3.25
3.20
3.15
3.10
3.05
1.260
1.255
1.250
1.245
1.240
1.235
-40
0
40
80
120
-40
0
40
80
120
Temperature(℃)
Temperature(℃)
Fig. 7 VVSEN vs. Temperature
Fig. 8 VREF vs. Temperature
7
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
LD8115A
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5.00
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
-40
0
40
80
120
Temperature(℃)
Fig. 9 VISEN_0 vs. Temperature
8
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
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08/02/2017
Application Information
Basic Description
Constant Current Control Loop
The LD8115A builds two Op-Amps including
high-accuracy reference voltage and dimmable function.
The CV (Constant voltage) loop Op-Amp is designed for
voltage control with it is non-inverting input internally
connects to the output of the shunt regulator. The CC
(constant current) loop Op-Amp is current control with a
low-side sense resistor. The sense resistor determines
the current regulation value. And the external R-C
components can compensate the two control loops.
The constant current loop includes an Op-amp and the
current sensing resistor. The ISEN pin is inverting input
of the current loop op amp. This pin is tied to the end of
the current sense resistor through a decoupling resistor
and the threshold voltage is 200mV. The maximum
current can be obtained from below.
200mꢀ
IOUT
=
ꢁꢂꢃ
ꢄ
ꢅꢆꢇ
Dimming Control
Maximum Output Voltage Setting
The device provides two dimming control is achieved by
applying an external PWM signal or direct analog
voltage to the DIM pin for brightness control. When
DCDIM pin input voltage larger than 2.5V the LED have
maximum brightness current. The DCDIM pin is
connected a filter capacitance for PWM signal transform
to dc voltage for adjustment LED Current Linearity.
Minimum adjustment voltage of VISEN is approach to 1%
around.
The main of the voltage control loop are an Op-amp and
high-accuracy reference voltage. The VSEN pin is
inverting input of the internal Op-amp. It connected to
the mid-point of a resistor divider that senses the senses
the output voltage. The internal precision reference is
1.25V. The OUT pin is connected Photo-coupler with
limit resistor to error signal to primary side for output
voltage regulation. The maximum output voltage is
determined by following relationship:
RA
VOUT_MAX = VꢀSEN(1 +
⁄
)
RB
200mV
where RA and RB are top and bottom feedback resistor
values.
Vout
RLimit
20mV
Opto
2mV
0V
OUT
0.25V
2.5V
Fig. 11
CV_Loop
VREF
RA
VSEN
Thermal protection
When the junction temperature reaches 130C
approximately, the thermal sensor signals would pull the
OUT to Low. The Photo-coupler would limit the output
voltage and reduce LED current. The thermal sensor will
RB
Fig. 10
9
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LD8115A
08/02/2017
turn on CC/CV loop again after the IC’s junction
temperature cools by 30C.
PCB Design Guideline
1.
The bypass capacitor of VCC should be placed as
close as possible to the VCC and GND pin of IC.
2.
Current Sense current loop should be as short as
possible between the ISEN and LD8115A GND
pin.
3.
4.
The traces of LED current loop should be as
strong and short as possible.
GND should be connected to a strong ground
plane.
VCC capacitor should
be placed as close as
possible to the VCC
PIN
VREF
ADIM
VCC
GND
OUT
8
7
6
5
1
2
3
4
DCDIM
ISEN
VSEN
VSEN Feedback
resistor should be
placed as close as
possible to the VSEN
and IC GND pin
Sense resistor should
be placed as close as
possible to the ISEN
and GND pin
Fig. 12
10
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
LD8115A
08/02/2017
Package Information
SOP-8
Dimensions in Millimeters
Dimensions in Inch
Symbols
MIN
MAX
MIN
MAX
A
B
C
D
4.801
3.810
1.346
0.330
5.004
3.988
1.753
0.508
0.189
0.150
0.053
0.013
0.197
0.157
0.069
0.020
F
H
I
1.194
0.178
0.102
5.791
0.406
0°
1.346
0.254
0.254
6.198
1.270
8°
0.047
0.007
0.004
0.228
0.016
0°
0.053
0.010
0.010
0.244
0.050
8°
J
M
θ
Important Notice
Leadtrend Technology Corp. reserves the right to make changes or corrections to its products at any time without notice. Customers
should verify the datasheets are current and complete before placing order.
11
Leadtrend Technology Corporation www.leadtrend.com.tw
LD8115A-DS-00 August 2017
LD8115A
08/02/2017
Revision History
REV.
00
Date
Change Notice
08/02/2017
Original Specification
12
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LD8115A-DS-00 August 2017
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