LR645 Datasheet, PDF (1/4 Pages) Supertex, Inc – High Input Voltage SMPS Start-up / Linear Regulator

LR645
High Input Voltage
SMPS Start-up / Linear Regulator
Ordering Information
Order Number / Package
Product marking for TO-243AA:
Max. Input Voltage TO-92 TO-243AA* TO-220 SO-8
Die
LR6❋
450V
LR645N3 LR645N8 LR645N5 LR645LG LR645ND
where ❋ = 2-week alpha date code
*Same as SOT-89. Product supplied on 2000 piece carrier tape reels.
Features
❏ Accepts inputs from 15V to 450V
❏ Compatible with industry standard PWM ICs.
See application note AN-H28.
❏ Output currents up to 3mA continuous, 30mA peak
❏ Supply current typically 50µA
❏ Line regulation typically 0.1mV/V
❏ Output can be trimmed from 8.0V to 12V
❏ Output current can be increased to 150mA with external FET
General Description
The Supertex LR6 is a high input voltage, low output current
linear regulator. It has a 3-terminal fixed output voltage version
available in TO-92, TO-220 and SOT-89 packages as well as an
adjustable voltage version available in 8 pin SOIC package. The
3-terminal version functions like any other low voltage 3-terminal
regulator except it allows the use of much higher input voltages.
When used in a SMPS start-up circuit, it eliminates the need for
large power resistors. In this application, current is drawn from
the high voltage line only during start-up. Only leakage current
flows after start-up thereby reducing the continuous power
dissipation to a few milliwatts.
Applications
❏ Off-line SMPS startup circuits (pulse loads)
❏ Low power off-line regulators
The adjustable voltage version allows trimming of the output
voltage from 8V to 12V. This version can also be connected to an
external depletion mode MOSFET for increased output current.
When used in conjunction with Supertex depletion mode MOSFET
DN2540N5, up to a 150mA is achieved.
❏ Regulators for noisy inputs
(continued on page 14-3)
Caution
Pin Configuration
The LR6 does NOT provide galvanic isolation. When
operated from an AC line, potentially lethal voltages can be
present on the IC. Adequate means of protecting the end
user from such voltages must be provided by the circuit
developer.
Absolute Maximum Ratings
TAB
1
2
3
TO-243AA
(SOT-89)
123
TO-92
TAB
Input Voltage
Output Voltage
Operating and Storage Temperature
450V
15.5V
–55°C to +150°C
5
123 ₄
SO-8
123
TO-220
Soldering Temperature*
*Distance of 1.6mm from case for 10 seconds
300°C
TO-92
+V
IN
1
GND
2
V
OUT
3
Trim
—
Gate
—
TO-243AA 1 2, TAB 3
—
—
For detailed circuit and application information, please refer
to application note AN-H28.
TO-220
P-DIP
1 2, TAB 3
1
3
4
—
—
5
7
11/12/01
Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability
indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to
workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the
Supertex website: http://www.supertex.com. For complete liability information on all Supertex prod₁ucts, refer to the most current databook or to the Legal/Disclaimer page on the Supertex website.