VIPER37
VIPerPlus family: fixed frequency offline converter
Datasheet
-
production data
•
High primary current protection (2
nd
OCP)
•
Input undervoltage setting (brownout)
•
Onboard soft-start
•
Safe auto-restart after a fault condition
•
Hysteretic thermal shutdown
Figure 1. Typical topology
+
DC input high voltage
wide range
Applications
+
DC Output voltage
•
SMPS for set-top boxes, DVD players and
recorders, white goods
•
Auxiliary power supply for consumer and home
equipment
•
ATX auxiliary power supply
•
Low / medium power AC-DC adapters
-
DRAIN DRAIN DRAIN DRAIN DRAIN
VIPER37
GND
VDD
CONT
FB
BR
Description
This device is an offline converter with an 800 V
rugged power section, a PWM control, two levels
Features
of overcurrent protection, overvoltage and
•
800 V avalanche-rugged power MOSFET
overload protection, hysteretic thermal protection,
allowing ultra wide range input V
ac
to be
soft-start, and safe auto-restart after the removal
achieved
of any fault condition. Burst mode operation and
very low device consumption help to meet the
•
PWM operation with adjustable limiting current
standby energy saving regulations. Advance
•
30 mW standby power at 265 V
ac
frequency jittering reduces EMI filter costs.
•
Operating frequency:
Brownout function protects the switch mode
–
60 kHz (L type), 115 kHz (H type)
power supply when the rectified input voltage
level is below the normal minimum level specified
•
Frequency jittering for low EMC
for the system. The high voltage startup circuit is
•
Output overvoltage protection
embedded in the device.
Table 1. Device summary
Order code
VIPER37LE
SDIP10
VIPER37HE
Tube
VIPER37HD
VIPER37LD
SO16 narrow
VIPER37HDTR
Tape and reel
VIPER37LDTR
July 2015
This is information on a product in full production.
Package
Packing
DocID022218 Rev 3
1/35
www.st.com
Contents
VIPER37
Contents
1
2
3
4
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Typical power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1
4.2
4.3
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5
6
7
8
Typical electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Typical circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Efficiency performances for a typical flyback converter . . . . . . . . . . . 16
Operation description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
8.9
8.10
8.11
8.12
8.13
Power section and gate driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
High voltage startup generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power-up and soft-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power down operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Auto-restart operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Current mode conversion with adjustable current limit set point . . . . . . . 21
Overvoltage protection (OVP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
About the CONT pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Feedback and overload protection (OLP) . . . . . . . . . . . . . . . . . . . . . . . . 24
Burst mode operation at no load or very light load . . . . . . . . . . . . . . . . . . 26
Brownout protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2nd level overcurrent protection and hiccup mode . . . . . . . . . . . . . . . . . . 29
9
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
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DocID022218 Rev 3
VIPER37
Contents
9.1
9.2
SDIP10 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
SO16 narrow package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
10
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
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Block diagram
VIPER37
1
Block diagram
Figure 2. Block diagram
BR
VDD
Vcc
DRAIN
+
Vin_OK
-
VBRth
15uA
UVLO
-
SOFT
START
OCP
BLOCK
OCP
BURST
TURN-ON
LOGIC
S
Q
R1
OSCILLATOR
Internal Supply bus
&
Ref erence Voltages
SUPPLY
& UVLO
HV_ON
Istart-up
THERMAL
SHUTDOWN
OTP
.
OVP
LOGIC
+
-
6uA
OVP
Ref
+
-
BURST-MODE
LOGIC
FB
2
Typical power
Table 2. Typical power
230 V
AC
Part number
VIPER37
Adapter
(1)
18 W
Open frame
(2)
20 W
Adapter
(1)
13 W
85-265 V
AC
Open frame
(2)
15 W
1. Typical continuous power in non-ventilated enclosed adapter measured at 50
°
C ambient.
2. Maximum practical continuous power in an open frame design at 50
°
C ambient, with adequate heatsinking.
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DocID022218 Rev 3
+
PWM
LEB
2nd OCP
LOGIC
BURST
CONT
R2
OLP
OVP
OTP
Rsense
GND
VIPER37
Pin settings
3
Pin settings
Figure 3. Connection diagram (top view)
Note:
The copper area for heat dissipation must be designed under the DRAIN pins.
Table 3. Pin description
Pin n.
Name
SO16N
1...2
3
GND
N.C.
This pin represents the device ground and the source of the power section.
Not connected.
Not available for user.
This pin is mechanically connected to the controller die pad of the frame.
In order to improve the noise immunity, is highly recommended connect it to GND
(pin 1-2).
Supply voltage of the control section. This pin also provides the charging current
of the external capacitor during start-up time.
Function
4
N.A.
5
VDD
6
Control pin. The following functions can be selected:
1. current limit set point adjustment. The internal set default value of the cycle-by-
cycle current limit can be reduced by connecting to ground an external resistor.
CONT
2. output voltage monitoring. A voltage exceeding V
OVP
threshold (see
Table 8 on
page 8)
shuts the IC down reducing the device consumption. This function is
strobed and digitally filtered for high noise immunity.
Control input for duty cycle control. Internal current generator provides bias
current for loop regulation. A voltage below the threshold V
FBbm
activates the
burst-mode operation. A level close to the threshold V
FBlin
means that we are
approaching the cycle-by-cycle over-current set point.
Brownout protection input with hysteresis. A voltage below the threshold V
BRth
shuts down (not latch) the device and lowers the power consumption. Device
operation restarts as the voltage exceeds the threshold V
BRth
+ V
BRhyst
. It can be
connected to ground when not used.
Not connected.
7
FB
8
BR
9...12
13...16
N.C.
High voltage drain pin. The built-in high voltage switched start-up bias current is
DRAIN drawn from this pin too.
Pins connected to the metal frame to facilitate heat dissipation.
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