VIPER53DIP-E STMicroelectronics, VIPER53DIP-E Datasheet - Page 25

• Manufacturer Part Number: VIPER53DIP-E
• Description: IC OFFLINE SWIT PWM CM OTP 8DIP
• Manufacturer: STMicroelectronics
• Series: VIPER™r
• Type: Pulse Width Modulator Controllerr

Specifications of VIPER53DIP-E

• Output Isolation: Isolated
• Frequency Range: 93 ~ 300kHz
• Voltage - Input: 8.4 ~ 19 V
• Voltage - Output: 620V
• Power (watts): 30W
• Operating Temperature: 25°C ~ 125°C
• Package / Case: 8-DIP (0.300", 7.62mm)
• Current, Supply: 9 mA
• Frequency, Oscillator: 100 kHz
• Package Type: DIP-8
• Regulator Type: Switching
• Resistance, Thermal, Junction To Case: 20 °C/W
• Temperature, Operating, Range: -40 to +150 °C
• Time, Fall: 100 ns
• Time, Rise: 50 ns
• Voltage, Supply: 13 V
• Power Switch Family: VIPer53DIP
• Input Voltage: 0 to 19V
• Power Switch On Resistance: 900mOhm
• Output Current: 1.6A
• Number Of Outputs: Single
• Mounting: Through Hole
• Supply Current: 9mA
• Operating Temperature (min): -40C
• Operating Temperature (max): 150C
• Operating Temperature Classification: Automotive
• Pin Count: 8
• Mounting Style: Through Hole
• For Use With: 497-8435 - BOARD EVAL FOR VIPER53 28W497-6458 - BOARD EVAL BASED ON VIPER53-E497-6262 - BOARD REF SGL VIPER53 90-264VAC497-5866 - EVAL BOARD 24W NEG OUT VIPER53E
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6171-5

VIPer53 - E
11
Transconductance error amplifier
The VIPer53-E includes a transconductance error amplifier. Transconductance Gm is the
change in output current I
Equation 8
The output impedance Z
Equation 9
This last equation shows that the open loop gain A
Equation 10
where Gm value for VIPer53 is typically 1.4mA/V.
Gm is well defined by specification, but Z
tolerances. An impedance Z must be connected between the COMP pin and ground in order
to accurately define the transfer function F of the error amplifier, the following equation, very
similar to the one above:
Equation 11
The error amplifier frequency response is shown in .0 for different values of a simple
resistance connected on the COMP pin. The unloaded transconductance error amplifier
shows an internal Z
the COMP pin to achieve different compensation methods. A capacitor provides an
integrator function, thus eliminating the DC static error, and a resistance in series leads to a
flat gain at higher frequency, introducing a zero level and ensuring a correct phase margin.
This configuration illustrated in
the error amplifier transfer function for a typical set of values of C
Note that a 10nF capacitor (8nF, minimum value) should always be connected to the COMP
pin to ensure a correct stability of the internal error amplifier.
The complete converter open loop transfer function can be built from both power cell and
error amplifier transfer functions. A theoretical example can be seen in
discontinuous mode flyback loaded by a simple resistor, regulated from primary side (no
COMP
COMP
COMP
of about 140K . More complex impedances can be connected on
Z
COMP
at the output of this amplifier (COMP pin) can be defined as:
Figure
versus change in input voltage V
A
=
VOL
F s
22, for the schematic and
--------------------- -
Gm
V
I
COMP
COMP,
COMP
=
=
=
Gm
Gm
------------------- -
=
I
COMP
and therefore A
V
--------- -
Gm
DD
Z
1
Z s
VOL
COMP
--------------------- -
can be related to Gm and Z
Transconductance error amplifier
V
V
COMP
DD
VOL,
Figure 23 on page 28
DD
COMP
. Thus:
are subject to large
and R
Figure 24
COMP
for a
.
COMP
for
25/36
: