SGP100SZ Fairchild Semiconductor, SGP100SZ Datasheet - Page 10

• Manufacturer Part Number: SGP100SZ
• Description: IC CTRLR PWM GREEN CM CV/CC 8SOP
• Manufacturer: Fairchild Semiconductor

Specifications of SGP100SZ

• Output Isolation: Isolated
• Frequency Range: 39 ~ 45kHz
• Voltage - Input: 6.75 ~ 30 V
• Voltage - Output: 18V
• Power (watts): 400mW
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Primary-side-control PWM Controller
OPERATION DESCRIPTION
The patented topology of SGP100 enables simplified
circuit design for battery charger applications. Without
secondary feedback circuitry, the CV and CC control can
be achieved accurately. As shown in Figure 2, with the
frequency-hopping PWM operation, EMI problem can be
solved using minimized filter components. SGP100 also
provides many protection functions. The VDD pin is
equipped with over-voltage protection and under-voltage
lockout. Pulse-by-pulse current limiting and CC control
ensure over-current protection at heavy loads. The GATE
output is clamped at 18V to protect the external MOSFET
from
over-temperature protection shuts down the controller
with latch when over heated.
Start-up Current
The start-up current is only 10µA. Low start-up current
allows a start-up resistor with high resistance and
low-wattage to supply the start-up power for the
controller. A 1.5MΩ, 0.25W start-up resistor and a
10µF/25V V
AC-to-DC power adapter with a wide input range (90V
to 264V
Operating Current
The operating current has been reduced to 6.5mA. The
low operating current results in higher efficiency and
reduces the V
Green-Mode Operation
Figure 3 shows the characteristics of the PWM frequency
vs. the output voltage of the error amplifier (V
© System General Corp.
Version 1.1.1 (IAO33.0042.B1)
over-voltage
AC
).
DD
Figure 2. Frequency Hopping
DD
Frequency Hopping Period
44.6KHz
hold-up capacitance requirement.
hold-up capacitor are sufficient for an
39.4KHz
Gate Signal
damage.
Also,
+/- 2.6KHz
→
3mS
the
COMV
internal
). The
AC
- 10 -
SGP100 uses the positive, proportional, output load
parameter (V
modulating the PWM frequency. In heavy load conditions,
the PWM frequency is fixed at 42KHz. Once V
lower than V
decrease from 42KHz to 500Hz (0.55V), providing
further power savings and meeting international power
conservation requirements.
Constant Voltage (CV) and
Constant Current (CC) Operation
An innovative technique of the SGP100 can accurately
achieve CV/CC characteristic output without secondary
side voltage or current-feedback circuitry. There is a
feedback signal for CV/CC operation from the reflected
voltage across the primary auxiliary winding. This
voltage signal is proportional to secondary winding, so it
provides controller the feedback signal from secondary
side
constant-current output, this voltage signal is detected and
examined by the precise constant current regulation
controller, which determines the on-time of the MOSFET
to control input power and provide constant-current
output.
current-sense resistor, the controller can obtain the input
power of power supply. Therefore, the region of constant
current output operation can be adjusted by a
current-sense resistor.
Figure 3. Green-Mode Operation Frequency vs. V
Frequency
42KHz
40KHz
500Hz
1KHz
and
With
COMV
www.sg.com.tw • www.fairchildsemi.com
achieves
N
, the PWM frequency starts to linearly
V
feedback
) as an indication of the output load for
G
constant-voltage
voltage
Product Specification
V
September 26, 2007
N
V
CS
output.
across
SGP100
V
COMV
COMV
COMV
the
In
is