|
|
PDF LD7536 Data sheet ( Hoja de datos )
| Número de pieza | LD7536 | |
| Descripción | Green-Mode PWM Controller | |
| Fabricantes | Leadtrend | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LD7536 (archivo pdf) en la parte inferior de esta página. Total 16 Páginas | ||
|
No Preview Available !
LD7536
12/15/2011
Green-Mode PWM Controller with Frequency Swapping
and Integrated Protections
Rev. 02a
General Description
The LD7536 is built-in with several functions, protection
and EMI-improved solution in a tiny package. It takes less
components counts or circuit space, especially ideal for
those total solutions of low cost.
The implemented functions include low startup current,
green-mode power-saving operation, leading-edge
blanking of the current sensing and internal slope
compensation. It also features more protections like
OLP (Over Load Protection) and OVP (Over Voltage
Protection) to prevent circuit damage occurred under
abnormal conditions.
Furthermore, the Frequency Swapping function is to
reduce the noise level and thus helps the power circuit
designers to easily deal with the EMI filter design by
spending minimum amount of component cost and
developing time.
Features
z High-Voltage CMOS Process with Excellent ESD
protection
z Very Low Startup Current (<20μA)
z Current Mode Control
z Green Mode Control
z UVLO (Under Voltage Lockout)
z LEB (Leading-Edge Blanking) on CS Pin
z Internal Frequency Swapping
z Internal Slope Compensation
z OVP (Over Voltage Protection) on Vcc Pin
z OTP (Over Temperature Protection) through a NTC
z OLP (Over Load Protection)
z 300mA Driving Capability
Applications
z Switching AC/DC Adaptor and Battery Charger
z Open Frame Switching Power Supply
Typical Application
Leadtrend Technology Corporation
LD7536-DS-02a December 2011
1
www.leadtrend.com.tw
1 page  
LD7536
Electrical Characteristics
(TA = +25°C unless otherwise stated, VCC=15.0V)
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Supply Voltage (Vcc Pin)
Startup Current
Operating Current
(with 1nF load on OUT pin)
VCOMP=0V
VCOMP=3V
OLP Tripped/ Auto
OVP Tripped/Latch
12 20
1.0
2.0
0.4
0.85
μA
mA
mA
mA
mA
OTP Pin Tripped/Latch
0.85 mA
Holding Current
UVLO (off)
Vcc=7V (latched)
430 μA
9 10 11 V
UVLO (on)
15 16 17
V
OVP Level
25 26 27
V
Voltage Feedback (Comp Pin)
Short Circuit Current
Open Loop Voltage
VCOMP=0V
COMP pin open
0.25 mA
5.4 V
Green Mode Threshold VCOMP
2.2 V
Zero Duty Threshold VCOMP
1.4 V
Zero Duty Hysteresis
100 mV
Current Sensing (CS Pin)
Maximum Input Voltage, VCS_OFF
Leading Edge Blanking Time
0.8 0.85 0.9
230
V
ns
Internal Slope Compensation
Input impedance
Delay to Output
0% to DMAX. (Linearly increase)
300
1
100
mV
MΩ
ns
Oscillator for Switching Frequency
Frequency, FREQ
60 65 70 kHz
Green Mode Frequency, FREQG
22 kHz
Trembling Frequency
Temp. Stability
Voltage Stability
(-20°C ~85°C)
(VCC=11V-25V)
± 4.0
5
1
kHz
%
%
Leadtrend Technology Corporation
LD7536-DS-02a December 2011
5
www.leadtrend.com.tw
5 Page 
LD7536
Internal Slope Compensation
In the conventional applications, the problem of the
stability is a critical issue for current mode controlling,
when it operates over 50% duty-cycle. As UC384X, It
takes slope compensation from injecting the ramp signal
of the RT/CT pin through a coupling capacitor. It therefore
requires no extra design for the LD7536 since it has
integrated it already.
On/Off Control
The LD7536 can be turned off by pulling COMP pin lower
than 1.4V. The gate output pin of the LD7536 will be
disabled immediately under such condition. The off-mode
can be released when the pull-low signal is removed.
Over Load Protection (OLP) - Auto
Recovery
To protect the circuit from damage due to over-load
condition and short or open-loop condition, the LD7536 is
implemented with smart OLP function. It also features
auto recovery function, see Fig. 18 for the waveform. In
case of fault condition, the feedback system will force the
voltage loop toward the saturation and then pull the
voltage high on COMP pin (VCOMP). When the VCOMP
ramps up to the OLP threshold of 4.5V and continues over
OLP delay time, the protection will be activated and then
turn off the gate output to stop the switching of power
circuit.
With the protection mechanism, the average input power
will be minimized to remain the component temperature
and stress within the safe operating area.
VCC
UVLO(on)
UVLO(off)
COMP
4.5V
OUT
OLP
UVLO(off)
OLP Reset
OLP delay time
OLP trip Level
t
t
Switching
Non-Switching
Switching
Fig. 18
t
OVP (Over Voltage Protection) on Vcc -
Latch mode
The Vcc OVP function of LD7536 is in latch mode. As
soon as the voltage of the Vcc pin rises above OVP
threshold, the output gate drive circuit will be shutdown
simultaneous to latch off the power MOSFET. On the
contrast, if the voltage on Vcc pin drops below OVP
threshold and starts AC-recycling again, it will soon
resume to normal operation. Fig. 19 shows its operation.
Leadtrend Technology Corporation
LD7536-DS-02a December 2011
11
www.leadtrend.com.tw
Fig. 19
11 Page | ||
| Páginas | Total 16 Páginas | |
| PDF Descargar | [ Datasheet LD7536.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LD7530 | Green-Mode PWM Controller |  Leadtrend Technology |
| LD7530A | Green-Mode PWM Controller | Leadtrend Technology |
| LD7531 | Green-Mode PWM Controller | Leadtrend Technology |
| LD7531A | Green-Mode PWM Controller | Leadtrend Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |