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PWM Controllers. MIC38HC45 Datasheet

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PWM Controllers. MIC38HC45 Datasheet






MIC38HC45 Controllers. Datasheet pdf. Equivalent




MIC38HC45 Controllers. Datasheet pdf. Equivalent





Part

MIC38HC45

Description

BiCMOS 1A Current-Mode PWM Controllers



Feature


MIC38HC42/3/4/5 Micrel MIC38HC42/3/4/5 BiCMOS 1A Current-Mode PWM Controllers Final Information General Description The MIC38HC4x family are fixed frequen cy current-mode PWM controllers with 1A drive current capability. Micrel’s B iCMOS devices are pin-compatible with 3 84x bipolar devices. Their high output drive, with fast rise and fall times, c ombined with low sta.
Manufacture

Micrel Semiconductor

Datasheet
Download MIC38HC45 Datasheet


Micrel Semiconductor MIC38HC45

MIC38HC45; rtup current make it an ideal PWM contro ller where high efficiency is required. Undervoltage lockout circuitry allows the ’42 and ’44 versions to start u p at 14.5V and operate down to 9V, and the ’43 and ’45 versions start at 8 .4V with operation down to 7.6V. All ve rsions operate up to 20V. When compared to bipolar UC384x devices operating fr om a µA 15V supply, start-.


Micrel Semiconductor MIC38HC45

up current has been reduced to 50 typica l and operating current has been reduce d to 4.0 mA typical. Decreased output r ise and fall times drive larger MOSFETs , and rail-to-rail output capability in creases efficiency, especially at lower supply voltages. The MIC38HC4x also fe atures a trimmed oscillator discharge c urrent and bandgap reference. MIC38HC4x -1 is available in.


Micrel Semiconductor MIC38HC45

14-pin plastic DIP and SOIC packages. 8 -pin devices feature small size, while 14-pin devices separate the analog and power connections for improved performa nce and power dissipation. Features Fast 20ns output rise and 15ns output fall times • –40°C to +85°C temp erature range exceeds UC284x specificat ions • High-performance, low-power Bi CMOS Process • Ultralow star.

Part

MIC38HC45

Description

BiCMOS 1A Current-Mode PWM Controllers



Feature


MIC38HC42/3/4/5 Micrel MIC38HC42/3/4/5 BiCMOS 1A Current-Mode PWM Controllers Final Information General Description The MIC38HC4x family are fixed frequen cy current-mode PWM controllers with 1A drive current capability. Micrel’s B iCMOS devices are pin-compatible with 3 84x bipolar devices. Their high output drive, with fast rise and fall times, c ombined with low sta.
Manufacture

Micrel Semiconductor

Datasheet
Download MIC38HC45 Datasheet




 MIC38HC45
MIC38HC42/3/4/5
Micrel
MIC38HC42/3/4/5
BiCMOS 1A Current-Mode PWM Controllers
Final Information
General Description
Features
The MIC38HC4x family are fixed frequency current-mode
PWM controllers with 1A drive current capability. Micrel’s
BiCMOS devices are pin-compatible with 384x bipolar de-
vices. Their high output drive, with fast rise and fall times,
combined with low startup current make it an ideal PWM
controller where high efficiency is required.
Undervoltage lockout circuitry allows the ’42 and ’44 versions
to start up at 14.5V and operate down to 9V, and the ’43 and
’45 versions start at 8.4V with operation down to 7.6V. All
versions operate up to 20V.
When compared to bipolar UC384x devices operating from a
15V supply, start-up current has been reduced to 50 µA
typical and operating current has been reduced to 4.0 mA
typical. Decreased output rise and fall times drive larger
MOSFETs, and rail-to-rail output capability increases effi-
ciency, especially at lower supply voltages. The MIC38HC4x
also features a trimmed oscillator discharge current and
bandgap reference.
MIC38HC4x-1 is available in 14-pin plastic DIP and SOIC
packages. 8-pin devices feature small size, while 14-pin
devices separate the analog and power connections for
improved performance and power dissipation.
• Fast 20ns output rise and 15ns output fall times
• –40°C to +85°C temperature range
exceeds UC284x specifications
• High-performance, low-power BiCMOS Process
• Ultralow start-up current (50µA typical)
• Low operating current (4mA typical)
• High output drive (1A peak current, HC version)
• CMOS outputs with rail-to-rail swing
• Current-mode operation up to 500kHz
• Trimmed 5V bandgap reference
• Pin-for-pin compatible with UC3842/3843/3844/3845(A)
• Trimmed oscillator discharge current
• UVLO with hysteresis
• Low cross-conduction currents
Applications
• Current-mode, off-line, switched-mode power supplies
• Current-mode, dc-to-dc converters.
• Step-down “buck” regulators
• Step-up “boost” regulators
• Flyback, isolated regulators
• Forward converters
• Synchronous FET converters
Functional Diagram
VDD
7 (12)
VREF
8 (14)
RT/CT
4 (7)
FB
2 (3)
2.5V
35V
5V
Reference
Oscillator
2R
R
UVLO
*
TQ
S
R
Q
(VD)
(11)
OUT
6 (10)
(PGND)
(8)
*
COMP GND*(AGND) ISNS
1 (1)
5 (9)
3 (5)
( ) pins are on MIC38HC4x-1 (14-lead) versions only
* MIC38HC4x (8-lead) versions only
MIC38HC42, MIC38HC43 (96% max. duty cycle) versions only
MIC38HC44, MIC38HC45 (50% max. duty cycle) versions only
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
http://www.Datasheet4U.com
August 2000
1 MIC38HC42/3/4/5




 MIC38HC45
MIC38HC42/3/4/5
Ordering Information
Part Number
MIC38HC42BN
MIC38HC43BN
MIC38HC44BN
MIC38HC45BN
MIC38HC42-1BN
MIC38HC43-1BN
MIC38HC44-1BN
MIC38HC45-1BN
MIC38HC42BM
MIC38HC43BM
MIC38HC44BM
MIC38HC45BM
MIC38HC42-1BM
MIC38HC43-1BM
MIC38HC44-1BM
MIC38HC45-1BM
Temperature Range
Package
40°C to +85°C 8-pin Plastic DIP
40°C to +85°C 8-pin Plastic DIP
40°C to +85°C 8-pin Plastic DIP
40°C to +85°C 8-pin Plastic DIP
40°C to +85°C 14-pin Plastic DIP
40°C to +85°C 14-pin Plastic DIP
40°C to +85°C 14-pin Plastic DIP
40°C to +85°C 14-pin Plastic DIP
40°C to +85°C
8-pin SOIC
40°C to +85°C
8-pin SOIC
40°C to +85°C
8-pin SOIC
40°C to +85°C
8-pin SOIC
40°C to +85°C
14-pin SOIC
40°C to +85°C
14-pin SOIC
40°C to +85°C
14-pin SOIC
40°C to +85°C
14-pin SOIC
Micrel
Selection Guide
Duty Cycle
0% to 96%
0% to 50%
UVLO Thresholds
Startup 8.4V
Startup 14.5V
Minimum Operating 7.6V Minimum Operating 9V
MIC38HC43
MIC38HC42
MIC38HC45
MIC38HC44
MIC38HC42/3/4/5
2
August 2000




 MIC38HC45
MIC38HC42/3/4/5
Pin Configuration
MIC38HC4x
COMP 1
8 VREF
FB 2
7 VDD
ISNS 3
6 OUT
RT/CT 4
5 GND
8-Pin DIP (N)
8-Lead SOIC (M)
Micrel
MIC38HC4x-1
COMP 1
NC 2
FB 3
NC 4
ISNS 5
NC 6
RT/CT 7
14 VREF
13 NC
12 VDD
11 VD
10 OUT
9 AGND
8 PGND
14-Pin DIP (-1BN)
14-Lead SOIC (-1BM)
Pin Description
Pin Number
N, M, MM
1
Pin Number
-1BN, -1BM
1
2
23
4
35
6
47
5
8
9
6 10
11
7 12
13
8 14
Pin Name
COMP
NC
FB
NC
ISNS
NC
RT/CT
GND
PGND
AGND
OUT
VD
VDD
NC
VREF
Pin Function
Compensation: Connect external compensation network to modify the error
amplifier output.
Not internally connected.
Feedback (Input): Error amplifier input. Feedback is 2.5V at desired output
voltage.
Not internally connected.
Current Sense (Input): Current sense comparator input. Connect to current
sensing resistor or current transformer.
Not internally connected.
Timing Resistor/Timing Capacitor: Connect external RC network to select
switching frequency.
Ground: Combined analog and power ground.
Power Ground: N-channel driver transistor ground.
Analog Ground: Controller circuitry ground.
Power Output: Totem-pole output.
Power Supply (Input): P-channel driver transistor supply input. Return to
power ground (PGND).
Analog Supply (Input): Controller circuitry supply input. Return to analog
ground (AGND).
Not internally connected.
5V Reference (Output): Connect external RC network.
August 2000
3 MIC38HC42/3/4/5



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