ROHM BP5034A12

Regulator ICs
AC / DC converter unit
The BP5034A12 is an AC / DC converter which can be used to supply 12V, 100mA DC output from a commercial power supply (100V AC). Using this unit enables simple, easy drive of microcomputers, LEDs, and other electronic components without using a transformer. It also allows set PCBs to be kept compact and lightweight, with extremely few attachments.
Power supply circuits for vacuum cleaners, washing machines, refrigerators, electric carpets, electric rice cookers and
hot water pots, irons, cordless telephones, air purifiers, humidifiers, dehumidifiers, illumination devices and other small
household appliances, as well as power supply circuits for gas, fire and smoke alarms, DC motors, sensors, and other
similar devices
1) Elimination of a transformer enables compact, lightweight power supply boards.
2) Wide input voltage range. (80 to 120V for AC voltage
3) DC circuits can be easily configured, with few attachments.
4) Since no transformer is used, the power supply board
is less vulnerable to splitting or cracking from impact
or shock.
5) Hybridization of the IC reduces the number of labor
hours in the assembly process.
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
Regulator ICs
Electrical characteristics (unless otherwise noted, Ta = 25C)
Electrical characteristics (unless otherwise noted, Ta = 25C)
Measurement circuit
Regulator ICs
Application example
Example showing charger of cordless telephone (hand-held set)
Basic power supply circuit
Half wave rectification circuit
Full wave rectification circuit
Regulator ICs
Selecting attached components
(1) Diodes
The rectifying diodes used should fulfill the following
In the absolute maximum ratings, the reverse surge current should be 400V or higher, the average rectifying current should be 0.5A or higher, and the forward surge voltage should be 20A or higher. For example, 1SR35 –400A
is recommended.
(2) Capacitor for input voltage smoothing
A capacitor with a larger valve produces a more stable
output voltage, but increases the surge current when the
power supply is turned on. The capacitor should have a
withstand resistance of at least 200V. Please refer to Figure 5 for examples of recommended capacitance values.
Operation notes
(1) The output current needs to be reduced as the ambient temperature rises.
(2) Lead pins should be securely soldered. If common
pins are not securely connected, or pins which are connected internally but which are not used are connected
to other pins, irregular voltages could be produced, causing breakdowns and damage.
(3) Over current and short circuit
The over current limit is a drooping model. At 25C, if
over current which exceeds the absolute maximum ratings is produced intermittently, or is produced continuously for a total of one minute or longer, the product is vulnerable to damage. If there is any danger of the load
being shorted or over current being produced, always
use a protective device such as a fuse.
(3) Capacitor for output voltage smoothing
This capacitor should have a low ESR. Capacitors designed for low-impedance switching power supplies are
especially suitable. The ESR of the capacitor affects the
output ripple voltage. Please refer to the table below for
the names of products made by various manufacturers.
(4) Avoid subjecting this product to strong impact.
(5) Regulations governing electrical products
As a stand-alone product, this product is not subject to
regulations governing electrical appliances. Please be
aware, therefore, that applications must be submitted for
sets and not for individual products.
(6) Insulation
This product is not insulated on the primary and secondary sides, and there is a danger of electrical shock if it is
(7) Connections with other devices
Devices using this product should not be connected to
other devices. If connected, insulation should be provided.
Regulator ICs
Electrical characteristic curves
External dimensions (Units: mm)