Bay Linear
Inspire the Linear Power
BiCMOS Current Mode PWM Controller
B38C42/43/44/45
Advance Information
Description
Features
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Low-Power BiCMOS Process
The Bay Linear B38C42/43/44/45 are fixed frequency and
high performance current-mode PWM controller in BiCMOS.
They are pin compatible with all bipolar 384X’s controllers are
similar to the MIC38C4X family. These devices are designed
for DC-to-DC converter applications and feature a trimmed
oscillator discharge current and bandgap reference.
Ultra Low Start-Up Current of 50µA (typ.)
Very Lower Operating Current (4mA)
Current Mode Operation ≥ 500KHz
CMOS outputs with Rail to Rail outputs
Under Voltage Lockout with Hysteresis
5V Trimmed Bandgap Reference
The benefit of the BiCMOS process provides significant
performance improvement compared to Bipolar 384X devices.
At 15VIN the start-up current is reduced to 50µA (typ.) from
0.17 mA with an operating current reduced to 4mA (typ.) from
14mA. Also, quicker output rise and fall times drive larger
MOSFET ‘s and rail-to-rail output capability improves
efficiency, especially lower supply voltages.
Trimmed Oscillator Discharged Current
Low Cross-Conduction Currents
Available in 8 pin SOIC and 8PDip
Similar to MIC38C42/43/44/45
Pin to Pin compatible with UC3842X Family
Major differences between members of these series are the
UVLO thresholds. Typical UVLO thresholds of 14.5V (on)
and 9V (off) for the B38C42 and B38C44 devices make them
ideally suited to off-line applications. The corresponding
typical thresholds for the B38C43 and B3845 devcies are 8.4V
(on) and 7.6V (off).
Applications
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Switched and Current Mode Power Supplies
Off-line Power Supply
Step-Up (Buck), Step-Down (Boost) Regulator
Flyback, Isolated Regulators
Synchronous FET converters
Forward Converters
The B39C4X devices are available in 8 pin DIP and SOIC.
Pin Connection
Ordering Information
Devices
Package
Temp.
B38C42M
SO-8
8-DIP
SO-8
8-DIP
SO-8
8-DIP
SO-8
8-DIP
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
B38C42P
B38C43M
B38C43P
B38C44M
B38C44P
B38C45M
B38C45P
8-SOIC and 8-PDip
COMP
1
2
3
4
8
7
6
5
REF
FB
VDD
OUTPUT
GND
ISENSE
RT/CT
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Bay Linear, Inc 2418 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com