Micrel MIC38HC45YM Bicmos 1a current-mode pwm controller Datasheet

MIC38HC42/3/4/5
Micrel, Inc.
MIC38HC42/3/4/5
BiCMOS 1A Current-Mode PWM Controllers
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 devices. 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 efficiency, 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)
35V
5V
Reference
VREF
8 (14)
UVLO
(VD)
(11)
†
Oscillator
RT/CT
OUT
4 (7)
6 (10)
FB
T
Q
S
R
Q
2R
2 (3)
2.5V
R
‡
(PGND)
(8)
*
COMP
1 (1)
GND*(AGND)
5
(9)
ISNS
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. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 2005
1
M9999-042205
MIC38HC42/3/4/5
Micrel, Inc.
Ordering Information
Standard
Part Number
Pb-Free
Junction
Temp. Range
Package
MIC38HC42BN
MIC38HC42YN
–40°C to +85°C
8-pin Plastic DIP
MIC38HC43BN
MIC38HC43YN
–40°C to +85°C
8-pin Plastic DIP
MIC38HC44BN
MIC38HC44YN
–40°C to +85°C
8-pin Plastic DIP
MIC38HC45BN
MIC38HC45YN
–40°C to +85°C
8-pin Plastic DIP
MIC38HC42-1BN
Contact Factory
–40°C to +85°C
14-pin Plastic DIP
MIC38HC43-1BN
Contact Factory
–40°C to +85°C
14-pin Plastic DIP
MIC38HC44-1BN
Contact Factory
–40°C to +85°C
14-pin Plastic DIP
MIC38HC45-1BN
Contact Factory
–40°C to +85°C
14-pin Plastic DIP
MIC38HC42BM
MIC38HC42YM
–40°C to +85°C
8-pin SOIC
MIC38HC43BM
MIC38HC43YM
–40°C to +85°C
8-pin SOIC
MIC38HC44BM
MIC38HC44YM
–40°C to +85°C
8-pin SOIC
MIC38HC45BM
MIC38HC45YM
–40°C to +85°C
8-pin SOIC
MIC38HC42-1BM
MIC38HC42-1YM
–40°C to +85°C
14-pin SOIC
MIC38HC43-1BM
MIC38HC43-1YM
–40°C to +85°C
14-pin SOIC
MIC38HC44-1BM
MIC38HC44-1YM
–40°C to +85°C
14-pin SOIC
MIC38HC45-1BM
MIC38HC45-1YM
–40°C to +85°C
14-pin SOIC
Selection Guide
UVLO Thresholds
M9999-042205
Duty Cycle
Startup 8.4V
Minimum Operating 7.6V
Startup 14.5V
Minimum Operating 9V
0% to 96%
MIC38HC43
MIC38HC42
0% to 50%
MIC38HC45
MIC38HC44
2
April 2005
MIC38HC42/3/4/5
Micrel, Inc.
Pin Configuration
MIC38HC4x-1
COMP 1
MIC38HC4x
14 VREF
NC 2
13 NC
FB 3
12 VDD
NC 4
11 VD
COMP 1
8
VREF
FB 2
7
VDD
NC 6
9 AGND
ISNS 3
6
OUT
RT/CT 7
8 PGND
RT/CT 4
5
GND
ISNS 5
8-Pin DIP (N)
8-Lead SOIC (M)
10 OUT
14-Pin DIP (-1BN)
14-Lead SOIC (-1BM)
Pin Description
Pin Number
N, M, MM
Pin Number
-1BN, -1BM
Pin Name
1
1
COMP
2
NC
Not internally connected.
3
FB
Feedback (Input): Error amplifier input. Feedback is 2.5V at desired output
voltage.
4
NC
Not internally connected.
5
ISNS
6
NC
7
RT/CT
2
3
4
5
6
7
8
April 2005
GND
Pin Function
Compensation: Connect external compensation network to modify the error
amplifier output.
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.
8
PGND
Power Ground: N-channel driver transistor ground.
9
AGND
Analog Ground: Controller circuitry ground.
10
OUT
11
VD
Power Supply (Input): P-channel driver transistor supply input. Return to
power ground (PGND).
12
VDD
Analog Supply (Input): Controller circuitry supply input. Return to analog
ground (AGND).
13
NC
14
VREF
Power Output: Totem-pole output.
Not internally connected.
5V Reference (Output): Connect external RC network.
3
M9999-042205
MIC38HC42/3/4/5
Micrel, Inc.
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
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
Output Voltage
TA = 25°C, IO = 1mA
4.90
5.00
5.10
V
Line Regulation
12V ≤ VDD ≤ 18V, IO = 5µA, Note 6
2
20
mV
Load Regulation
1 ≤ IO ≤ 20mA
1
25
mV
Temp. Stability
Note 1
Total Output Variation
Line, Load, Temp., Note 1
Output Noise Voltage
10Hz ≤ f ≤ 10kHz, TA = 25°C, Note 1
50
Long Term Stability
TA = 125°C, 1000 hrs., Note 1
5
25
mV
–30
–80
–180
mA
49
52
55
kHz
1.0
%
Reference Section
0.2
4.82
Output Short Circuit
mV/°C
5.18
V
µV
Oscillator Section
Initial Accuracy
TA = 25°C, Note 5
Voltage Stability
12 ≤ VDD ≤ 18V, Note 6
0.2
Temp. Stability
TMIN ≤ TA ≤ TMAX, Note 1
0.04
Clock Ramp
Reset Current
TA = 25°C, VRT/CT = 2V
TA = TMIN to TMAX
Amplitude
VRT/CT peak to peak
7.7
7.2
8.4
8.4
%/°C
9.0
9.5
1.9
mA
mA
Vp-p
Error Amp Section
Input Voltage
VCOMP = 2.5V
Input Bias Current
VFB = 5.0V
AVOL
2 ≤ VO ≤ 4V
65
90
dB
Unity Gain Bandwidth
Note 1
0.7
1.0
MHz
PSRR
12 ≤ VDD ≤ 18V
60
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
M9999-042205
2.42
2.50
2.58
V
–0.1
–2
µA
dB
0.1
4
1.1
V
April 2005
MIC38HC42/3/4/5
Parameter
Micrel, Inc.
Test Conditions
Min
Typ
Max
Units
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
Current Sense
70
dB
Input Bias Current
–0.1
–2
µA
Delay to Output
120
250
ns
Output
RDS(ON) ‘HC’ High
RDS(ON) ‘HC’ Low
ISOURCE = 200mA
ISINK = 200mA
10
5.5
Rise Time
TA = 25°C, CL = 1nF
20
50
ns
Fall Time
TA = 25°C, CL = 1nF
15
40
ns
Ω
Ω
Undervoltage Lockout
Start Threshold
Minimum Operating Voltage
MIC38HC42/4
13.5
14.5
15.5
V
MIC38HC43/5
7.8
8.4
9.0
V
MIC38HC42/4
8
9
10
V
MIC38HC43/5
7.0
7.6
8.2
V
MIC38HC42/3
94
96
%
MIC38HC44/5
46
50
%
Pulse Width Modulator
Maximum Duty Cycle
Minimum Duty Cycle
0
%
Total Standby Current
Start-Up Current
VDD = 13V, 38HC42/44
VDD = 7.5V, 38HC43/45
50
200
µA
Operating Supply Current
VFB = VISNS = 0V
4.0
6.0
mA
Zener Voltage (VDD)
IDD = 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 =
∆ VPIN1
; 0 ≤ VTH (ISNS ) ≤ 0.8V
VTH (ISNS )
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.
April 2005
5
M9999-042205
MIC38HC42/3/4/5
Micrel, Inc.
MIC38C/HC42/43 Output Dead
Time vs. Oscillator Frequency
100
200pF
470pF
1nF
1.8nF
10
4.7nF
10nF
OUTPUT DEAD TIME (%)
RT RESISTANCE (kΩ)
100
VDD = 15V
1.2
1.0
125°C
0.8
0.6
25°C
0.4
-50°C
0
2
4
6
8
ERROR AMPLIFIER OUTPUT (V)
M9999-042205
10
200pF
10nF
470pF
1nF
1
1x104
VREF SHORT CURCUIT CURRENT (mA)
CURRENT SENSE AMP THRESHOLD (V)
Current Sense Amplifier
vs. Error Amplifier Output
0.0
4.7nF
18nF
1
1x104
1x105
1x106
OSCILLATOR FREQUENCY (Hz)
0.2
VDD = 15V
1x105
FREQUENCY (Hz)
1x106
Oscillator Discharge
Current vs. Temperature
9.0
8.8
8.6
8.4
8.2
8.0
7.8
7.6
7.4
VDD = 15V
VOSC = 2V
7.2
7.0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Short-Circuit Reference
Current vs. Temperature
MIC38C4x
Output Waveform
120
25
100
80
60
40
20
VDD = 15V
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
6
OUTPUT VOLTAGE (V)
Oscillator Frequency
Configuration
OSC. DISCHARGE CURRENT (mA)
Typical Characteristics
20
15
10
5
0
-5
-10
-15
0.0
VD = 15V
CL = 1nF
0.2
0.4
0.6
TIME (µs)
0.8
1.0
April 2005
MIC38HC42/3/4/5
Micrel, Inc.
Package Information
PIN 1
DIMENSIONS:
INCH (MM)
0.380 (9.65)
0.370 (9.40)
0.255 (6.48)
0.245 (6.22)
0.135 (3.43)
0.125 (3.18)
0.300 (7.62)
0.013 (0.330)
0.010 (0.254)
0.018 (0.57)
0.380 (9.65)
0.320 (8.13)
0.130 (3.30)
0.100 (2.54)
0.0375 (0.952)
8-Pin Plastic DIP (N)
.770 (19.558) MAX
PIN 1
.235 (5.969)
.215 (5.461)
.060 (1.524)
.045 (1.143)
.310 (7.874)
.280 (7.112)
.160 MAX
(4.064)
.080 (1.524)
.015 (0.381)
.015 (0.381)
.008 (0.2032)
.160 (4.064)
.100 (2.540)
.110 (2.794)
.090 (2.296)
.023 (.5842)
.015 (.3810)
.060 (1.524)
.045 (1.143)
.400 (10.180)
.330 (8.362)
14-Pin Plastic DIP (N)
April 2005
7
M9999-042205
MIC38HC42/3/4/5
Micrel, Inc.
0.026 (0.65)
MAX)
PIN 1
0.157 (3.99)
0.150 (3.81)
DIMENSIONS:
INCHES (MM)
0.020 (0.51)
0.013 (0.33)
0.050 (1.27)
TYP
0.064 (1.63)
0.045 (1.14)
45°
0.0098 (0.249)
0.0040 (0.102)
0°–8°
0.197 (5.0)
0.189 (4.8)
SEATING
PLANE
0.010 (0.25)
0.007 (0.18)
0.050 (1.27)
0.016 (0.40)
0.244 (6.20)
0.228 (5.79)
8-Pin SOIC (M)
PIN 1
DIMENSIONS:
INCHES (MM)
0.154 (3.90)
0.026 (0.65)
MAX)
0.193 (4.90)
0.050 (1.27) 0.016 (0.40)
TYP
TYP
45°
0.006 (0.15)
0.057 (1.45)
0.049 (1.25)
0.344 (8.75)
0.337 (8.55)
3°–6°
0.244 (6.20)
0.228 (5.80)
SEATING
PLANE
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.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
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.
© 2000 Micrel Incorporated
M9999-042205
8
April 2005
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