UC2844BD1R2G
The UC3844B and UC3845B series are resolved frequency current mode controllers with high performance. They are specifically designed for O?ine and dc-dc converter applications, providing the designer with a cost efficient solution that requires few external components. These integrated circuits include an oscillator, a temperature compensated reference, a high gain error amplifier, a current sensing comparator, and a high current totem pole output suitable for driving a power MOSFET. There are also protective features such as input and reference under voltage lockouts with hysteresis, cycle by cycle current limiting, a latch for single pulse metering, and a flipflop that blanks the output off every other oscillator cycle, allowing output deadtimes to be programmed from 50% to 70%.
These devices come in both an 8pin dual-in-line and surface mount (SOIC8) and a 14pin plastic surface mount (SOIC14) packaging. The totem pole output stage features independent power and ground pins in the SOIC14 package. UVLO thresholds of 16 V (on) and 10 V (off) make the UCX844B an excellent choice for off-line converters. With UVLO thresholds of 8.5 V (on) and 7.6 V (off), the UCX845B is designed for low-voltage applications (off).
Features
?Pb?Free Packages are Available
?Trimmed Oscillator for Precise Frequency Control
?Oscillator Frequency Guaranteed at 250 kHz
?Current Mode Operation to 500 kHz Output Switching Frequency
?Output Deadtime Adjustable from 50% to 70%
?Automatic Feed Forward Compensation
?Latching PWM for Cycle?By?Cycle Current Limiting
?Internally Trimmed Reference with Undervoltage Lockout
?High Current Totem Pole Output
?Under voltage Lockout with Hysteresis
?Low Startup and Operating Current
UC3610DW
This eight-diode array is designed for
high-current, low duty-cycle applications typical of
flyback voltage clamping for inductive loads. The
dual bridge connection makes this device
particularly applicable to bipolar driven stepper
motors.
The use of Schottky diode technology features
high efficiency through lowered forward voltage
drop and decreased reverse recovery time.
This single monolithic chip is fabricated in both
hermetic CERDIP and copper-leaded plastic
packages. The UC1610 in ceramic is designed for
?55?C to 125?C environments but with reduced
peak current capability. The UC2610 in plastic and
ceramic is designed for ?25?C to 125?C
environments also with reduced peak current
capability; while the UC3610 in plastic has higher
current rating over a 0?C to 70?C temperature
range.
UC3611N
This four-diode array is designed for general
purpose use as individual diodes or as a
high-speed, high-current bridge. It is particularly
useful on the outputs of high-speed power
MOSFET drivers where Schottky diodes are
needed to clamp any negative excursions caused
by ringing on the driven line.These diodes are also
ideally suited for use as voltage clamps when
driving inductive loads such as relays and
solenoids, and to provide a path for current
free-wheeling in motor drive applications.The use
of Schottky diode technology features high
efficiency through lowered forward voltage drop
and decreased reverse recovery time.This single
monolithic chip is fabricated in both hermetic
CERDIP and copper-eaded plastic packages.
The UC1611 in ceramic is designed for ?55?C to
125?C environments but with reduced peak
current capability: while the UC3611 in plastic has
higher current rating over a 0?C to 70?C ambient
temperature range
UC3823AN
The UC3823A and UC3823B and the UC3825A and
UC3825B family of PWM controllers are improved
versions of the standard UC3823 and UC3825 family.
Performance enhancements have been made to several
of the circuit blocks. Error amplifier gain bandwidth product
is 12 MHz, while input offset voltage is 2 mV. Current limit
threshold is assured to a tolerance of 5%. Oscillator
discharge current is specified at 10 mA for accurate dead
time control. Frequency accuracy is improved to 6%.
Startup supply current, typically 100 ?A, is ideal for off-line
applications. The output drivers are redesigned to actively
sink current during UVLO at no expense to the startup
current specification. In addition each output is capable of
2-A peak currents during transitions
UC3844N
The UCx84x series of control integrated circuits
provide the features that are necessary to implement
off-line or DC-to-DC fixed-frequency current-mode
control schemes, with a minimum number of external
components. The internally implemented circuits
include an undervoltage lockout (UVLO), featuring a
start-up current of less than 1 mA, and a precision
reference trimmed for accuracy at the error amplifier
input. Other internal circuits include logic to ensure
latched operation, a pulse-width modulation (PWM)
comparator that also provides current-limit control,
and a totem-pole output stage that is designed to
source or sink high-peak current. The output stage,
suitable for driving N-channel MOSFETs, is low when
it is in the off state.
UCC2813D-2
The UCC3813-x device family of high-speed, lowpower integrated circuits contains all of the control
and drive components required for off-line and DC-toDC fixed-frequency current-mode switching power
supplies with minimal parts count.
These devices have the same pin configuration as
the UC384x device family, and also offer the added
features of internal full-cycle soft start and internal
leading-edge blanking of the current-sense input.
The UCC3813-x device family offers a variety of
package options, temperature-range options, choice
of maximum duty cycle, and choice of critical voltage
levels. Devices with lower reference voltage such as
the UCC3813-3 and UCC3813-5 fit best into battery
operated systems, while the higher reference and the
higher UVLO hysteresis of the UCC3813-2 device
and UCC3813-4 device make these ideal choices for
use in off-line power supplies.
UCC3750DW
The UCC3750 Source Ringer Controller provides a complete control and
drive solution for a four quadrant flyback-based ring generator circuit. The
IC controls a primary side switch, which is modulated when power transfer
is taking place from input to output. It also controls two secondary
switches which act as synchronous rectifier switches during positive
power flow. These switches are pulse-width-modulated when the power is
being delivered back to the source
UCC3800N
The UCC280x family of high-speed, low-power
integrated circuits contain all of the control and drive
components required for off-line and DC-to-DC fixed
frequency current-mode switching mode power
supplies with minimal parts count.
These devices have the same pin configuration as the
UCx84x family, and also offer the added features of
internal full-cycle soft start and internal leading-edge
blanking of the current-sense input.
