UCC25800-Q1
SLUSDX3B – NOVEMBER 2020 – REVISED NOVEMBER 2021
UCC25800-Q1 Ultra-low EMI Transformer Driver for Isolated Bias Supplies
The transformer driver has a programmable frequency
1 Features
range of 100 kHz to 1.2 MHz. This high switching
frequency reduces the transformer size and footprint,
as well as the overall cost of the bias supply. The
integrated SYNC function allows the system bias
supplies to synchronize with an external clock signal,
further reducing the system level noise.
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High-efficiency half-bridge transformer driver
Ultra-low EMI with low interwinding capacitance
Smaller and lower-cost transformer
– Programmable frequency: 0.1 MHz to 1.2 MHz
Wide input voltage range: 9 V to 34 V
– 9 W from 34-V input
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The dead-time adjusts automatically to minimize
the conduction loss and simplify the design. The
programmable maximum dead-time ensures power
stage design flexibility.
– 6 W from 24-V input
– 4 W from 15-V input
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Automatic dead-time adjustment with maximum
dead-time programming
With the integrated, low-resistance switching power
stage, the transformer driver can achieve a 6-W
design with 24-V input, and up to 9-W from 34-V
input. With a fixed input voltage, the open-loop control
also helps the output regulation to remain ±5% when
the load is above 10%.
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External clock synchronization for low noise
Robust protection features
– Undervoltage lockout (UVLO)
– Programmable over-current protection (OCP)
– Input overvoltage protection (OVP)
– Over temperature protection (TSD)
– Integrated soft-start to reduce in-rush current
– External disable function with fault-code output
AEC-Q100 qualified for automotive applications:
– Temperature grade 1: –40°C to +125°C, TA
Functional Safety-Capable
– Documentation available to aid functional safety
system design
The programmable overcurrent protection (OCP)
allows flexibility on the power stage design to
minimize the transformer size. The protection features
such as adjustable OCP, input OVP, TSD and the
protection from pin faults ensure robust operation.
A fixed 1.5-ms soft-start period reduces the inrush
current during start-up and fault recovery.
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8-Pin DGN package with thermal pad
The transformer driver also provides a dedicated
multi-function pin for external disabling, and fault code
reporting. The fault code reporting sends the fault
code once the bias supply is in the protection mode.
2 Applications
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Automotive traction inverter & motor control
Automotive on-board charger (OBC)
Automotive DC/DC converter
EV charging station, DC fast charging station
UPS and solar inverters
Industrial motors, elevators and escalators
GaN, IGBT and SiC gate transformer driver bias
supply
The UCC25800-Q1 transformer driver is offered in an
8-pin DGN package with the thermal pad to enhance
its thermal handling capability.
Device Information
PART NUMBER
PACKAGE(1)
BODY SIZE (NOM)
UCC25800-Q1
HVSSOP (8)
3.00 mm × 3.00 mm
3 Description
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
The UCC25800-Q1 ultra-low EMI transformer driver
integrates the switching power stage, the control, and
the protection circuits to simplify isolated bias supply
designs. It allows the design to utilize a transformer
with higher leakage inductance, but much smaller
parasitic primary-to-secondary capacitance. This low-
capacitance transformer design enables an order of
magnitude reduction in the common-mode current
injection through the bias transformer. This makes the
transformer driver an ideal solution for the isolated
bias supply in various automotive applications to
minimize the EMI noise caused by the high-speed
switching devices. The soft-switching feature further
reduces the EMI noise.
VIN
SYNC
VCC
DIS/FLT
VREG
SW
VOUT
GND
OC/DT
RT
Simplified Application
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.