Leadtrend LD7535ABL, LD7535AGL, LD7535BL, LD7535GL, LD7535ABN Schematic [ru]
...
Rev. 01c
LD7535/LD7535A
12/11/2007
Green-Mode PWM Controller with Integrated Protections
General Description
The LD7535/LD7535A are low cost, low startup current,
current mode PWM controllers with green-mode power-
saving operation. The integrated functions include the
leading-edge blanking of the current sensing, internal slope
compensation and the tiny package of SOT-26. They
provide the users a superior AC/DC power application of
higher efficiency, low external component counts, and lower
cost solution.
Furthermore, LD7535/LD7535A features more protections
like OLP (Over Load Protection) and OVP (Over Voltage
Protection) to eliminate the external protection circuits. And
to satisfy different designs, 2 versions of OVP levels are
implemented as ---
z LD7535 --- 28.0V ± 1.5V.
z LD7535A --- 21.0V ± 1.5V.
Typical Application
Features
z High-Voltage CMOS Process with Excellent ESD
protection
z Very Low Startup Current (<20μA)
z Current Mode Control
z Non-audible-noise Green Mode Control
z UVLO (Under Voltage Lockout)
z LEB (Leading-Edge Blanking) on CS Pin
z Programmable Switching Frequency
z Internal Slope Compensation
z OVP (Over Voltage Protection) on Vcc Pin
z OLP (Over Load Protection)
z 300mA Driving Capability
Applications
z Switching AC/DC Adaptor and Battery Charger
z Open Frame Switching Power Supply
z 384X Replacement
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Leadtrend Technology Corporation www.leadtrend.com.tw
LD7535&LD7535A-DS-01c December 2007
LD7535/LD7535A
Pin Configuration (LD7535)
DIP-8 (TOP VIEW)
GND
COMP
7 6 5
TOP MARK
YYWW##
1 8 2 3 4
OUT
VCC
YY, Y : Year code (D: 2004, E: 2005…..)
WW, W: Week code
P : LD75..
## : Production code
Pin Configuration (LD7535A)
DIP-8 (TOP VIEW)
GND
COMP
7 6 5
TOP MARK
YYWW##
NC
RT
CS
NC
(Product family code)
NC
RT
SOT-26 (TOP VIEW)
456
35
WP
Y
123
The PB free package is identified
Y
in embossed font while green
package in regular font.
SOT-26 (TOP VIEW)
35A
WP
Y
123
456
1 8 2 3 4
CS
OUT
YY, Y : Year code (D: 2004, E: 2005…..)
WW, W: Week code
P : LD75..
## : Production code
NC
VCC
(Product family code)
Y
Ordering Information
Part number Package TOP MARK Shipping
LD7535 BL SOT-26 PB Free YWP/35 3000 /tape & reel
LD7535 GL SOT-26 Green Package YWP/35 3000 /tape & reel
LD7535 BN DIP-8 PB Free LD7535BN 3600 /tube /Carton
LD7535A BL SOT-26 PB Free YWP/35A 3000 /tape & reel
LD7535A GL SOT-26 Green Package YWP/35A 3000 /tape & reel
LD7535A BN DIP-8 PB Free LD7535ABN 3600 /tube /Carton
The LD7535/ LD7535A are ROHS Complaint/ Green Package.
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Leadtrend Technology Corporation www.leadtrend.com.tw
LD7535&LD7535A-DS-01c December 2007
The PB free package is identified
in embossed font while green
package in regular font.
Pin Descriptions
PIN NAME FUNCTION
1 GND Ground
2 COMP
3 RT
4 CS Current sense pin, connect to sense the MOSFET current
5 VCC Supply voltage pin
6 OUT Gate drive output to drive the external MOSFET
LD7535/LD7535A
Voltage feedback pin (same as the COMP pin in UC384X), By connecting
a photo-coupler to close the control loop and achieve the regulation.
This pin is to program the switching frequency. By connecting a resistor
to ground to set the switching frequency.
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Leadtrend Technology Corporation www.leadtrend.com.tw
LD7535&LD7535A-DS-01c December 2007
∑
Block Diagram
LD7535/LD7535A
*
Note: OLP delay is 60mS when the switching frequency is set as 65KHz.
The OLP delay time is proportional to the period of switching cycle.
1
That is,
TT =∝
.
sdelay_OLP
f
s
4
Leadtrend Technology Corporation www.leadtrend.com.tw
LD7535&LD7535A-DS-01c December 2007
LD7535/LD7535A
Absolute Maximum Ratings
Supply Voltage VCC 30V
COMP, RT, CS
Junction Temperature
Operating Ambient Temperature
Storage Temperature Range
Package Thermal Resistance (SOT-26)
Package Thermal Resistance (DIP-8)
Power Dissipation (SOT-26, at Ambient Temperature = 85°C)
Power Dissipation (DIP-8, at Ambient Temperature = 85°C)
Lead temperature (Soldering, 10sec)
ESD Voltage Protection, Human Body Model
ESD Voltage Protection, Machine Model
Gate Output Current 300mA
-0.3 ~7V
150°C
-40°C to 85°C
-65°C to 150°C
250°C/W
100°C/W
250mW
650mW
260°C
3KV
250V
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 Min. Max. Unit
Supply Voltage Vcc (LD7535) 11 25 V
Supply Voltage Vcc (LD7535A) 11 18 V
Switching Frequency 50 130 KHz
Startup Resistor Value 1.2 4.4 MΩ
5
Leadtrend Technology Corporation www.leadtrend.com.tw
LD7535&LD7535A-DS-01c December 2007
LD7535/LD7535A
Electrical Characteristics
(TA = +25oC unless otherwise stated, VCC=15.0V)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Supply Voltage (Vcc Pin)
Startup Current 8 20 μA
V
=0V 2.0 3.0 mA
Operating Current
(with 1nF load on OUT pin)
UVLO (off) 9.0 10.0 11.0 V
UVLO (on) 15.0 16.0 17.0 V
OVP Level
Voltage Feedback (Comp Pin)
Short Circuit Current V
Open Loop Voltage COMP pin open 6.0 V
Green Mode Threshold VCOMP 2.35 V
Current Sensing (CS Pin)
Maximum Input Voltage, Vcs(off) 0.80 0.85 0.90 V
Leading Edge Blanking Time 350 nS
Input impedance 1 MΩ
Delay to Output 100 nS
Oscillator (RT pin)
Frequency RT=100KΩ 60 65 70 KHz
Green Mode Frequency Fs=65KHz 20 KHz
Temp. Stability (-40°C ~105°C) 3 %
Voltage Stability (VCC=11V-25V) 1 %
Gate Drive Output (OUT Pin)
Output Low Level VCC=15V, Io=20mA 1 V
Output High Level VCC=15V, Io=20mA 8 V
Rising Time Load Capacitance=1000pF 50 200 nS
Falling Time Load Capacitance=1000pF 30 100 nS
OLP (Over Load Protection)
OLP Trip Level V
OLP Delay Time (note) Fs=65KHz 60 mS
Note: The OLP delay time is proportional to the period of switching cycle. So that, the lower RT value will set the higher switching
frequency and the shorter OLP delay time.
COMP
V
=3V 2.5 mA
COMP
Protection tripped (OLP, OVP) 0.5 mA
LD7535 26.5 28.0 29.5 V
LD7535A 19.5 21.0 22.5 V
=0V 1.5 2.2 mA
COMP
(OLP) 5.0 V
COMP
6
Leadtrend Technology Corporation www.leadtrend.com.tw
LD7535&LD7535A-DS-01c December 2007
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