TOP414

Manufacturer Part NumberTOP414
DescriptionThree-terminal DC to DC PWM Switch
ManufacturerPower Integrations Inc.
TOP414 datasheet
 
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TOP412/414
TOPSwitch Family
Three-terminal DC to DC PWM Switch
Product Highlights
Low Cost Replacement for Discrete Switchers
• Up to 15 fewer components - cuts cost, increases reliability
• Allows for a smaller and lighter solution under 12 mm
height, all surface mount components
Over 80% Efficiency in Flyback Topology
• Built-in start-up and current limit reduce DC losses
• Low capacitance MOSFET cuts switching losses
• CMOS controller/gate driver consumes only 7 mW
• 70% maximum duty cycle minimizes conduction losses
Simplifies Design - Reduces Time to Market
• Integrated PWM Controller and high power MOSFET
• Only one external capacitor needed for compensation,
bypass and start-up/auto-restart functions
System Level Fault Protection Features
• Auto-restart and cycle by cycle current limiting functions
handle both primary and secondary faults
• On-chip latching thermal shutdown protects the entire
system against overload
Highly Versatile
• Implements Buck, Boost, Flyback or Forward topology
• Easily interfaces with both opto and primary feedback
• Supports continuous or discontinuous mode of operation
• Specified for operation down to 16 V DC input
Description
The TOPSwitch family implements, with only three terminals,
all functions necessary for a DC to DC, converter: high voltage
N-channel power MOSFET with controlled turn-on gate driver,
voltage mode PWM controller with integrated 120 kHz oscillator,
high voltage start-up bias circuit, bandgap derived reference,
bias shunt regulator/error amplifier for loop compensation and
fault protection circuitry. Compared to discrete MOSFET and
controller or self oscillating (RCC) switching converter solutions,
a TOPSwitch integrated circuit can reduce total cost, component
count, size, weight and at the same time increase efficiency and
system reliability.
This device is well suited for Telecom,
Cablecom and other DC to DC converter applications up to
®
V IN
Figure 1. Typical Application.
Table 1. TOP412/414 Output Power.
Notes: 1. Assumes maximum junction temperature of 100 C
2. Assumes output of 5 V and K
(645 mm
power capability in a given application depends on thermal
environment, transformer design, efficiency required, input storage
capacity, etc.
21W of output power. Internally, the lead frame of the
SMD-8 package uses six of its pins to transfer heat from the chip
directly to the board, eliminating the cost of a heat sink.
D
CONTROL
C
TOP414
S
Output Power Capability
MINIMUM
ORDER PART NUMBER
INPUT
TOP412G
VOLTAGE
18 VDC
3 W
24 VDC
5 W
36 VDC
7 W
48 VDC
9 W
12 W
60 VDC
72 VDC
15 W
90 VDC
18 W
of 0.4 3. Soldered to 1 sq. inch
RP
2
), 2 oz. copper clad (610 gm/mm
®
V O
PI-2371-120198
1-4
TOP414G
4 W
6 W
9 W
12 W
15 W
18 W
21 W
2
) 4. The continuous
April 1999

TOP414 Summary of contents

  • Page 1

    ... TOP412G VOLTAGE 18 VDC VDC VDC VDC VDC 72 VDC VDC 0.4 3. Soldered to 1 sq. inch oz. copper clad (610 gm/mm ® PI-2371-120198 1-4 TOP414G The continuous April 1999 ...

  • Page 2

    TOP412/414 V C CONTROL Z C SHUNT REGULATOR/ ERROR AMPLIFIER - + 5 OSCILLATOR D MAX CLOCK SAW R E Figure 2. Functional Block Diagram. Pin Functional Description DRAIN Pin: Output MOSFET drain connection. Provides internal bias ...

  • Page 3

    TOPSwitch Family Functional Description TOPSwitch is a self biased and protected linear control current- to-duty cycle converter with an open drain output. High efficiency is achieved through the use of CMOS and integration of the maximum number of functions possible. ...

  • Page 4

    TOP412/414 TOPSwitch Family Functional Description (cont.) The first time V reaches the upper threshold, the high-voltage C current source is turned off and the PWM modulator and output transistor are activated, as shown in Figure 5(a). During normal operation (when ...

  • Page 5

    DRAIN 0 V OUT 0 I OUT Figure 6. Typical Waveforms for (1) Normal Operation, (2) Auto-restart, (3) Latching Shutdown, and (4) Power Down Reset. CONTROL ...

  • Page 6

    ... TOP412/414 General Circuit Operation Figure 7 shows a typical DC-DC converter application using the TOP414G. This supply delivers and works over a wide input range from 36-72 VDC. The power supply operates at an ambient temperature of 0- order to achieve the highest possible efficiency and smallest ...

  • Page 7

    ... Use single point grounding techniques at the SOURCE pin as shown in Figure 8. Use a ceramic high frequency decoupling capacitor to bypass noise transients which might appear on the CONTROL pin. The TOP412 and TOP414 have an over current latching shutdown feature. Failure to use a high frequency decoupling capacitor may allow incidental noise to accidentally trigger this feature ...

  • Page 8

    ... SOURCE = -40 to 125 mA 0.5 mA, See Figure 9 C CD1 TOP412 mA, C See Figure 9 TOP414 mA See Figure 4 See Note A See Figure mA See Figure 10 (1) (2) ................ -40 to 150 C (3) ................................................ 260 C ...

  • Page 9

    ... See Note A S1 open S1 open S1 open S1 open S1 open TOP412 di/dt = 400 mA TOP414 di/dt = 600 mA See Figure 10 S2 open TOP412/414 Min Typ Max Units -2.4 -1 ...

  • Page 10

    ... Device in Latched Shutdown mA 500 Measured With Figure 7 Schematic Measured With Figure 7 Schematic See Note TOP412 Output MOSFET Enabled TOP414 Output MOSFET Disabled Min Typ Max Units 2.6 3.0 4.2 5.0 1.7 2.0 2.8 3.3 500 A V 350 ns 100 ns 50 ...

  • Page 11

    ... ON time is the difference between the input voltage and the drain voltage (V ). DS(ON) For example, if the input voltage is 16 VDC and a TOP414 (2.95 A minimum current limit) is used at a primary peak current of 1A. Then the (V primary Conditions (Unless Otherwise Specified) ...

  • Page 12

    TOP412/414 90% DRAIN VOLTAGE 10 Figure 9. TOPSwitch Duty Cycle Measurement. D CONTROL TOPSwitch S NOTES: 1. This test circuit is not applicable for current limit or output characteristic measurements. 2. For P ...

  • Page 13

    BENCH TEST PRECAUTIONS FOR EVALUATION OF ELECTRICAL CHARACTERISTICS The following precautions should be followed when testing TOPSwitch by itself outside of a power supply. The schematic shown in Figure 11 is suggested for laboratory testing of TOPSwitch. When the DRAIN ...

  • Page 14

    ... Drain Voltage ( 4/99 Scaling Factors: TOP414 1.00 TOP412 0. DRAIN CAPACITANCE POWER 100 Scaling Factors: TOP414 1.00 TOP412 0. 160 240 DRAIN Voltage (V) C OSS vs. DRAIN VOLTAGE 1000 Scaling Factors: TOP414 1.00 TOP412 0.67 100 160 240 DRAIN Voltage (V) 320 320 ...

  • Page 15

    D S .004 (.10 - G08A J2 .010 (.25 SMD-8 Heat Sink is 2 oz. Copper As Big As Possible .046 .060 .060 .046 ...

  • Page 16

    TOP412/414 For the latest updates, visit our Web site: www.powerint.com Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power Integrations does not assume any liability arising from the use ...