Off-Line Switcher. TNY280GN Datasheet

TNY280GN Switcher. Datasheet pdf. Equivalent


Power Integrations TNY280GN
TNY274-280
TinySwitch®-III Family
Energy-Efficient, Off-Line Switcher With
Enhanced Flexibility and Extended Power Range
Product Highlights
Lowest System Cost with Enhanced Flexibility
Simple ON/OFF control, no loop compensation needed
Selectable current limit through BP/M capacitor value
Higher current limit extends peak power or, in open
frame applications, maximum continuous power
Lower current limit improves efficiency in enclosed
adapters/chargers
Allows optimum TinySwitch-III choice by swapping
devices with no other circuit redesign
Tight I2f parameter tolerance reduces system cost
Maximizes MOSFET and magnetics power delivery
Minimizes max overload power, reducing cost of
transformer, primary clamp & secondary components
ON-time extension – extends low line regulation range/hold-up
time to reduce input bulk capacitance
Self-biased: no bias winding or bias components
Frequency jittering reduces EMI filter costs
Pin-out simplifies heatsinking to the PCB
SOURCE pins are electrically quiet for low EMI
Enhanced Safety and Reliability Features
Accurate hysteretic thermal shutdown protection with
automatic recovery eliminates need for manual reset
Improved auto-restart delivers <3% of maximum power in short
circuit and open loop fault conditions
Output overvoltage shutdown with optional Zener
Line undervoltage detect threshold set using a single optional
resistor
Very low component count enhances reliability and enables
single-sided printed circuit board layout
High bandwidth provides fast turn on with no overshoot and
excellent transient load response
Extended creepage between DRAIN and all other pins improves
field reliability
EcoSmart®– Extremely Energy Efficient
Easily meets all global energy efficiency regulations
No-load <150 mW at 265 VAC without bias winding, <50 mW
with bias winding
ON/OFF control provides constant efficiency down to very light
loads – ideal for mandatory CEC regulations and 1 W PC
standby requirements
Applications
Chargers/adapters for cell/cordless phones, PDAs, digital
cameras, MP3/portable audio, shavers, etc.
PC Standby and other auxiliary supplies
DVD/PVR and other low power set top decoders
Supplies for appliances, industrial systems, metering, etc.
+
Wide-Range
HV DC Input
D
EN/UV
TinySwitch-III
BP/M
S
-
Figure 1. Typical Standby Application.
+
DC
Output
-
PI-4095-082205
Output Power Table
230 VAC ± 15%
Product3
Adapter1
Peak or
Open
Frame2
TNY274P/G
6W
11 W
TNY275P/G
8.5 W
15 W
TNY276P/G
10 W
19 W
TNY277P/G
13 W
23.5 W
TNY278P/G
16 W
28 W
TNY279P/G
18 W
32 W
TNY280P/G
20 W
36.5 W
85-265 VAC
Adapter1
Peak or
Open
Frame2
5W
8.5 W
6W
11.5 W
7W
15 W
8W
18 W
10 W
21.5 W
12 W
25 W
14 W
28.5 W
Table 1. Output Power Table.
Notes:
1. Minimum continuous power in a typical non-ventilated enclosed adapter
measured at +50 °C ambient. Use of an external heatsink will increase power
capability.
2. Minimum peak power capability in any design or minimum continuous power in
an open frame design (see Key Applications Considerations).
3. Packages: P: DIP-8C, G: SMD-8C. See Part Ordering Information.
Description
TinySwitch-III incorporates a 700 V power MOSFET, oscillator,
high voltage switched current source, current limit (user
selectable) and thermal shutdown circuitry. The IC family uses an
ON/OFF control scheme and offers a design flexible solution with
a low system cost and extended power capability.
www.powerint.com
January 2009


TNY280GN Datasheet
Recommendation TNY280GN Datasheet
Part TNY280GN
Description Energy Efficient / Off-Line Switcher
Feature TNY280GN; TNY274-280 TinySwitch®-III Family Energy-Efficient, Off-Line Switcher With Enhanced Flexibility and .
Manufacture Power Integrations
Datasheet
Download TNY280GN Datasheet




Power Integrations TNY280GN
TNY274-280
BYPASS/
MULTI-FUNCTION
(BP/M)
115 μA
25 μA
LINE UNDER-VOLTAGE
FAULT
PRESENT
AUTO-
RESTART
COUNTER
6.4 V
RESET
ENABLE
1.0 V + VT
ENABLE/
UNDER-
VOLTAGE
(EN/UV)
1.0 V
JITTER
CLOCK
DCMAX
OSCILLATOR
OVP
LATCH
REGULATOR
5.85 V
DRAIN
(D)
+
BYPASS
CAPACITOR
-
SELECT AND
CURRENT
5.85 V
4.9 V
LIMIT STATE
MACHINE
BYPASS PIN
UNDER-VOLTAGE
VILIMIT
CURRENT LIMIT
COMPARATOR
THERMAL
SHUTDOWN
S
Q
R
Q
LEADING
EDGE
BLANKING
SOURCE
(S)
PI-4077-062306
Figure 2. Functional Block Diagram.
Pin Functional Description
DRAIN (D) Pin:
This pin is the power MOSFET drain connection. It provides
internal operating current for both startup and steady-state
operation.
BYPASS/MULTI-FUNCTION (BP/M) Pin:
This pin has multiple functions:
1. It is the connection point for an external bypass capacitor for
the internally generated 5.85 V supply.
2. It is a mode selector for the current limit value, depending on
the value of the capacitance added. Use of a 0.1 μF
capacitor results in the standard current limit value. Use of a
1 μF capacitor results in the current limit being reduced to
that of the next smaller device size. Use of a 10 μF capacitor
results in the current limit being increased to that of the next
larger device size for TNY275-280.
3. It provides a shutdown function. When the current into the
bypass pin exceeds I , the device latches off until the
SD
BP/M voltage drops below 4.9 V, during a power down. This
can be used to provide an output overvoltage function with a
Zener connected from the BP/M pin to a bias winding supply.
P Package (DIP-8C)
G Package (SMD-8C)
EN/UV 1
BP/M 2
D4
8S
7S
6S
5S
PI-4078-080905
Figure 3. Pin Configuration.
ENABLE/UNDERVOLTAGE (EN/UV) Pin:
This pin has dual functions: enable input and line undervoltage
sense. During normal operation, switching of the power
MOSFET is controlled by this pin. MOSFET switching is
terminated when a current greater than a threshold current is
drawn from this pin. Switching resumes when the current being
2
Rev. I 01/09
www.powerint.com



Power Integrations TNY280GN
TNY274-280
pulled from the pin drops to less than a threshold current. A
modulation of the threshold current reduces group pulsing. The
threshold current is between 75 μA and 115 μA.
measured with the oscilloscope triggered at the falling edge of
the DRAIN waveform. The waveform in Figure 4 illustrates the
frequency jitter.
The EN/UV pin also senses line undervoltage conditions through
an external resistor connected to the DC line voltage. If there is
no external resistor connected to this pin, TinySwitch-III detects
its absence and disables the line undervoltage function.
SOURCE (S) Pin:
This pin is internally connected to the output MOSFET source for
high voltage power return and control circuit common.
TinySwitch-III Functional Description
TinySwitch-III combines a high voltage power MOSFET switch
with a power supply controller in one device. Unlike conventional
PWM (pulse width modulator) controllers, it uses a simple
ON/OFF control to regulate the output voltage.
The controller consists of an oscillator, enable circuit (sense and
logic), current limit state machine, 5.85 V regulator, BYPASS/
MULTI-FUNCTION pin undervoltage, overvoltage circuit, and
current limit selection circuitry, over-temperature protection,
current limit circuit, leading edge blanking, and a 700 V power
MOSFET. TinySwitch-III incorporates additional circuitry for line
undervoltage sense, auto-restart, adaptive switching cycle on-
time extension, and frequency jitter. Figure 2 shows the
functional block diagram with the most important features.
Oscillator
The typical oscillator frequency is internally set to an average of
132 kHz. Two signals are generated from the oscillator: the
maximum duty cycle signal (DCMAX) and the clock signal that
indicates the beginning of each cycle.
The oscillator incorporates circuitry that introduces a small
amount of frequency jitter, typically 8 kHz peak-to-peak, to
minimize EMI emission. The modulation rate of the frequency
jitter is set to 1 kHz to optimize EMI reduction for both average
and quasi-peak emissions. The frequency jitter should be
600
500
400
VDRAIN
300
200
100
Enable Input and Current Limit State Machine
The enable input circuit at the EN/UV pin consists of a low
impedance source follower output set at 1.2 V. The current
through the source follower is limited to 115 μA. When the
current out of this pin exceeds the threshold current, a low logic
level (disable) is generated at the output of the enable circuit,
until the current out of this pin is reduced to less than the
threshold current. This enable circuit output is sampled at the
beginning of each cycle on the rising edge of the clock signal. If
high, the power MOSFET is turned on for that cycle (enabled). If
low, the power MOSFET remains off (disabled). Since the
sampling is done only at the beginning of each cycle,
subsequent changes in the EN/UV pin voltage or current during
the remainder of the cycle are ignored.
The current limit state machine reduces the current limit by
discrete amounts at light loads when TinySwitch-III is likely to
switch in the audible frequency range. The lower current limit
raises the effective switching frequency above the audio range
and reduces the transformer flux density, including the
associated audible noise. The state machine monitors the
sequence of enable events to determine the load condition and
adjusts the current limit level accordingly in discrete amounts.
Under most operating conditions (except when close to no-
load), the low impedance of the source follower keeps the
voltage on the EN/UV pin from going much below 1.2 V in the
disabled state. This improves the response time of the
optocoupler that is usually connected to this pin.
5.85 V Regulator and 6.4 V Shunt Voltage Clamp
The 5.85 V regulator charges the bypass capacitor connected
to the BYPASS pin to 5.85 V by drawing a current from the
voltage on the DRAIN pin whenever the MOSFET is off. The
BYPASS/MULTI-FUNCTION pin is the internal supply voltage
node. When the MOSFET is on, the device operates from the
energy stored in the bypass capacitor. Extremely low power
consumption of the internal circuitry allows TinySwitch-III to
operate continuously from current it takes from the DRAIN pin.
A bypass capacitor value of 0.1 μF is sufficient for both high
frequency decoupling and energy storage.
In addition, there is a 6.4 V shunt regulator clamping the
BYPASS/MULTI-FUNCTION pin at 6.4 V when current is
provided to the BYPASS/MULTI-FUNCTION pin through an
external resistor. This facilitates powering of TinySwitch-III
externally through a bias winding to decrease the no-load
consumption to well below 50 mW.
0
136 kHz
128 kHz
0
Figure 4. Frequency Jitter.
5
Time (μs)
BYPASS/MULTI-FUNCTION Pin Undervoltage
The BYPASS/MULTI-FUNCTION pin undervoltage circuitry
disables the power MOSFET when the BYPASS/MULTI-
FUNCTION pin voltage drops below 4.9 V in steady state
operation. Once the BYPASS/MULTI-FUNCTION pin voltage
10
drops below 4.9 V in steady state operation, it must rise back to
5.85 V to enable (turn-on) the power MOSFET.
www.powerint.com
3
Rev. I 01/09





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