Microchip Technology 的 MIC38HC42, 43, 44, 45 规格书

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MIC38HC42/3/4/5 Micrel, Inc.
April 2005 1 M9999-042205
MIC38HC42/3/4/5
BiCMOS 1A Current-Mode PWM Controllers
General Description
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 50µA
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.
Functional Diagram
Features
•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
TQ
S
RQ
R
2R
Oscillator
UVLO
5V
Reference
VDD
7 (12)
VREF
8 (14)
RT/CT
4 (7)
FB
2 (3)
2.5V
COMP
1 (1)
GND*(AGND)
5 (9)
ISNS
3 (5)
(VD)
(11)
OUT
6 (10)
(PGND)
(8)
( ) 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
†
‡
35V
*
*
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
MIC38HC42/3/4/5 Micrel, Inc.
M9999-042205 2April 2005
Ordering Information
Part Number Junction
Standard Pb-Free Temp. Range Package
MIC38HC42BN MIC38HC42YN –40°C to +85°C8-pin Plastic DIP
MIC38HC43BN MIC38HC43YN –40°C to +85°C8-pin Plastic DIP
MIC38HC44BN MIC38HC44YN –40°C to +85°C8-pin Plastic DIP
MIC38HC45BN MIC38HC45YN –40°C to +85°C8-pin Plastic DIP
MIC38HC42-1BN Contact Factory –40°C to +85°C14-pin Plastic DIP
MIC38HC43-1BN Contact Factory –40°C to +85°C14-pin Plastic DIP
MIC38HC44-1BN Contact Factory –40°C to +85°C14-pin Plastic DIP
MIC38HC45-1BN Contact Factory –40°C to +85°C14-pin Plastic DIP
MIC38HC42BM MIC38HC42YM –40°C to +85°C8-pin SOIC
MIC38HC43BM MIC38HC43YM –40°C to +85°C8-pin SOIC
MIC38HC44BM MIC38HC44YM –40°C to +85°C8-pin SOIC
MIC38HC45BM MIC38HC45YM –40°C to +85°C8-pin SOIC
MIC38HC42-1BM MIC38HC42-1YM –40°C to +85°C14-pin SOIC
MIC38HC43-1BM MIC38HC43-1YM –40°C to +85°C14-pin SOIC
MIC38HC44-1BM MIC38HC44-1YM –40°C to +85°C14-pin SOIC
MIC38HC45-1BM MIC38HC45-1YM –40°C to +85°C14-pin SOIC
UVLO Thresholds
Startup 8.4V Startup 14.5V
Duty Cycle Minimum Operating 7.6V Minimum Operating 9V
0% to 96% MIC38HC43 MIC38HC42
0% to 50% MIC38HC45 MIC38HC44
Selection Guide
3333333 EEEEEEE
MIC38HC42/3/4/5 Micrel, Inc.
April 2005 3 M9999-042205
Pin Description
Pin Number Pin Number Pin Name Pin Function
N, M, MM -1BN, -1BM
11COMP Compensation: Connect external compensation network to modify the error
amplifier output.
2NCNot internally connected.
23 FB Feedback (Input): Error amplifier input. Feedback is 2.5V at desired output
voltage.
4NCNot internally connected.
35 ISNS Current Sense (Input): Current sense comparator input. Connect to current
sensing resistor or current transformer.
6NCNot internally connected.
47RT/CT Timing Resistor/Timing Capacitor: Connect external RC network to select
switching frequency.
5GND Ground: Combined analog and power ground.
8PGND Power Ground: N-channel driver transistor ground.
9AGND Analog Ground: Controller circuitry ground.
610 OUT Power Output: Totem-pole output.
11 VD Power Supply (Input): P-channel driver transistor supply input. Return to
power ground (PGND).
712 VDD Analog Supply (Input): Controller circuitry supply input. Return to analog
ground (AGND).
13 NC Not internally connected.
814 VREF 5V Reference (Output): Connect external RC network.
1
2
3
4
8
7
6
5
COMP
FB
ISNS
RT/CT
VREF
VDD
OUT
GND
MIC38HC4x
2NC NC13
3FB VDD12
4NC VD11
5ISNS OUT10
6NC AGND9
7RT/CT PGND8
1COMP VREF14
MIC38HC4x-1
8-Pin DIP (N)
8-Lead SOIC (M)
14-Pin DIP (-1BN)
14-Lead SOIC (-1BM)
Pin Configuration
MIC38HC42/3/4/5 Micrel, Inc.
M9999-042205 4April 2005
Electrical Characteristics
VDD = 15V, Note 4; RT = 9.09kΩ; CT = 3.3nF; –40°C ≤ TA ≤ 85°C; unless noted
Parameter Test Conditions Min Typ Max Units
Reference Section
Output Voltage TA = 25°C, IO = 1mA 4.90 5.00 5.10 V
Line Regulation 12V ≤ VDD ≤ 18V, IO = 5µA, Note 6 220mV
Load Regulation 1 ≤ IO ≤ 20mA 1 25 mV
Temp. Stability Note 1 0.2 mV/°C
Total Output Variation Line, Load, Temp., Note 1 4.82 5.18 V
Output Noise Voltage 10Hz ≤ f ≤ 10kHz, TA = 25°C, Note 1 50 µV
Long Term Stability TA = 125°C, 1000 hrs., Note 1 525mV
Output Short Circuit –30 –80 –180 mA
Oscillator Section
Initial Accuracy TA = 25°C, Note 5 49 52 55 kHz
Voltage Stability 12 ≤ VDD ≤ 18V, Note 6 0.2 1.0 %
Temp. Stability TMIN ≤ TA ≤ TMAX, Note 1 0.04 %/°C
Clock Ramp TA = 25°C, VRT/CT = 2V 7.7 8.4 9.0 mA
Reset Current TA = TMIN to TMAX 7.2 8.4 9.5 mA
Amplitude VRT/CT peak to peak 1.9 Vp-p
Error Amp Section
Input Voltage VCOMP = 2.5V 2.42 2.50 2.58 V
Input Bias Current VFB = 5.0V –0.1 –2 µA
AVOL 2 ≤ VO ≤ 4V 65 90 dB
Unity Gain Bandwidth Note 1 0.7 1.0 MHz
PSRR 12 ≤ VDD ≤ 18V 60 dB
Output Sink Current VFB = 2.7V, VCOMP = 1.1V 2 14 mA
Output Source Current VFB = 2.3V, VCOMP = 5V –0.5 –1 mA
VOUT High VFB = 2.3V, RL = 15k to ground 5 6.8 V
VOUT Low VFB = 2.7V, RL = 15k to VREF 0.1 1.1 V
Absolute Maximum Ratings
Zener Current (VDD)...................................................30mA
Operation at ≥18V may require
special precautions (Note 6).
Supply Voltage (VDD), Note 6 .......................................20V
Switch Supply Voltage (VD) ..........................................20V
Current Sense Voltage (VISNS) ..................... –0.3V to 5.5V
Feedback Voltage (VFB) ................................ –0.3V to 5.5V
Output Current, 38HC42/3/4/5 (IOUT)..............................1A
Operating Junction Temperature (TJ) ....................... 150°C
Package Thermal Resistance
8-Pin Plastic DIP (θJA) .......................................125°C/W
8-Pin MM8™ (θJA) .............................................250°C/W
8-Pin SOIC (θJA) ...............................................170°C/W
14-Pin Plastic DIP (θJA) .......................................90°C/W
14-Pin SOIC (θJA) .............................................145°C/W
Storage Temperature (TA) ....................... –65°C to +150°C
MIC38HC42/3/4/5 Micrel, Inc.
April 2005 5 M9999-042205
Parameter Test Conditions Min Typ Max Units
Current Sense
Gain Notes 2, 3 2.85 3.0 3.15 V/V
MaximumThreshold VCOMP = 5V, Note 2 0.9 1 1.1 V
PSRR 12 ≤ VDD ≤ 18V, Note 2 70 dB
Input Bias Current –0.1 –2 µA
Delay to Output 120 250 ns
Output
RDS(ON) ‘HC’ High ISOURCE = 200mA 10 Ω
RDS(ON) ‘HC’ Low ISINK = 200mA 5.5 Ω
Rise Time TA = 25°C, CL = 1nF 20 50 ns
Fall Time TA = 25°C, CL = 1nF 15 40 ns
Undervoltage Lockout
Start Threshold MIC38HC42/4 13.5 14.5 15.5 V
MIC38HC43/5 7.8 8.4 9.0 V
Minimum Operating Voltage MIC38HC42/4 8 9 10 V
MIC38HC43/5 7.0 7.6 8.2 V
Pulse Width Modulator
Maximum Duty Cycle MIC38HC42/3 94 96 %
MIC38HC44/5 46 50 %
Minimum Duty Cycle 0%
Total Standby Current
Start-Up Current VDD = 13V, 38HC42/44 50 200 µA
VDD = 7.5V, 38HC43/45
Operating Supply Current VFB = VISNS = 0V 4.0 6.0 mA
Zener Voltage (VDD)I
DD = 25mA, Note 6 30 37 V
Note 1: These parameters, although guaranteed, are not 100% tested in production.
Note 2: Parameter measured at trip point of latch with VEA = 0.
Note 3: Gain defined as:
A = V
V (I )
0 V (I ) 0.8V
PIN1
TH SNS
TH SNS
∆;≤≤
Note 4: Adjust VDD above the start threshold before setting at 15V.
Note 5: Output frequency equals oscillator frequency for the MIC38HC42 and MIC38HC43. Output frequency for the MIC38HC44, and
MIC38HC45 equals one half the oscillator frequency.
Note 6: On 8-pin version, 20V is maximum input on pin 7, as this is also the supply pin for the output stage. On 14-pin version, 40V is
maximum for pin 12 and 20V maximum for pin 11.
MIC38HC42/3/4/5 Micrel, Inc.
M9999-042205 6April 2005
Typical Characteristics
1
10
100
1x10
4
1x10
5
1x10
6
R
T
RESISTANCE (kΩ)
OSCILLATOR FREQUENCY (Hz)
Oscillator Frequency
Configuration
10nF
4.7nF
1nF
470pF
200pF
1.8nF
V
DD
= 15V
1
10
100
1x10
4
1x10
5
1x10
6
OUTPUT DEAD TIME (%)
FREQUENCY (Hz)
MIC38C/HC42/43 Output Dead
Time vs. Oscillator Frequency
V
DD
= 15V
10nF
4.7nF
200pF
470pF
18nF
1nF
7.0
7.2
7.4
7.6
7.8
8.0
8.2
8.4
8.6
8.8
9.0
-60 -30 0 30 60 90 120 150
OSC. DISCHARGE CURRENT (mA)
TEMPERATURE (°C)
Oscillator Discharge
Current vs. Temperature
V
DD
= 15V
V
OSC
= 2V
0.0
0.2
0.4
0.6
0.8
1.0
1.2
02468
CURRENT SENSE AMP THRESHOLD (V)
ERROR AMPLIFIER OUTPUT (V)
Current Sense Amplifier
vs. Error Amplifier Output
-50°C
25°C
125°C
0
20
40
60
80
100
120
-60 -30 0 30 60 90 120 150
VREF SHORT CURCUIT CURRENT (mA)
TEMPERATURE (°C)
Short-Circuit Reference
Current vs. Temperature
VDD = 15V
-15
-10
-5
0
5
10
15
20
25
0.0 0.2 0.4 0.6 0.8 1.0
OUTPUT VOLTAGE (V)
TIME (µs)
MIC38C4x
Output Waveform
VD = 15V
CL = 1nF
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MIC38HC42/3/4/5 Micrel, Inc.
April 2005 7 M9999-042205
Package Information
0.380 (9.65)
0.370 (9.40)
0.135 (3.43)
0.125 (3.18)
PIN 1
DIMENSIONS:
INCH (MM)
0.018 (0.57)
0.100 (2.54)
0.013 (0.330)
0.010 (0.254)
0.300 (7.62)
0.255 (6.48)
0.245 (6.22)
0.380 (9.65)
0.320 (8.13)
0.0375 (0.952)
0.130 (3.30)
8-Pin Plastic DIP (N)
.080 (1.524)
.015 (0.381)
.023 (.5842)
.015 (.3810)
.310 (7.874)
.280 (7.112)
.770 (19.558) MAX
.235 (5.969)
.215 (5.461)
.060 (1.524)
.045 (1.143)
.160 MAX
(4.064)
.160 (4.064)
.100 (2.540) .110 (2.794)
.090 (2.296) .400 (10.180)
.330 (8.362)
.015 (0.381)
.008 (0.2032)
.060 (1.524)
.045 (1.143)
PIN 1
14-Pin Plastic DIP (N)
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MIC38HC42/3/4/5 Micrel, Inc.
M9999-042205 8April 2005
45°
0°–8°
0.244 (6.20)
0.228 (5.79)
0.197 (5.0)
0.189 (4.8) SEATING
PLANE
0.026 (0.65)
MAX)
0.010 (0.25)
0.007 (0.18)
0.064 (1.63)
0.045 (1.14)
0.0098 (0.249)
0.0040 (0.102)
0.020 (0.51)
0.013 (0.33)
0.157 (3.99)
0.150 (3.81)
0.050 (1.27)
TYP
PIN 1
DIMENSIONS:
INCHES (MM)
0.050 (1.27)
0.016 (0.40)
8-Pin SOIC (M)
45°
3°–6°
0.244 (6.20)
0.228 (5.80)
0.344 (8.75)
0.337 (8.55)
0.006 (0.15)
SEATING
PLANE
0.026 (0.65)
MAX)0.016 (0.40)
TYP
0.154 (3.90)
0.057 (1.45)
0.049 (1.25)
0.193 (4.90)
0.050 (1.27)
TYP
PIN 1
DIMENSIONS:
INCHES (MM)
14-Pin SOIC (M)
MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
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the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s
use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
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