|
|
PDF MIC2182 Data sheet ( Hoja de datos )
| Número de pieza | MIC2182 | |
| Descripción | High-Efficiency Synchronous Buck Controller | |
| Fabricantes | Micrel Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MIC2182 (archivo pdf) en la parte inferior de esta página. Total 28 Páginas | ||
|
No Preview Available !
MIC2182
Micrel
MIC2182
High-Efficiency Synchronous Buck Controller
General Description
Micrel’s MIC2182 is a synchronous buck (step-down) switch-
ing regulator controller. An all N-channel synchronous archi-
tecture and powerful output drivers allow up to a 20A output
current capabilty. The PWM and skip-mode control scheme
allows efficiency to exceed 95% over a wide range of load
current, making it ideal for battery powered applications, as
well as high current distributed power supplies.
The MIC2182 operates from a 4.5V to 32V input and can
operate with a maximum duty cycle of 86% for use in low-
dropout conditions. It also features a shutdown mode that
reduces quiescent current to 0.1µA.
The MIC2182 achieves high efficiency over a wide output
current range by automatically switching between PWM and
skip mode. Skip-mode operation enables the converter to
maintain high efficiency at light loads by turning off circuitry
pertaining to PWM operation, reducing the no-load supply
current from 1.6mA to 600µA. The operating mode is inter-
nally selected according to the output load conditions. Skip
mode can be defeated by pulling the PWM pin low which
reduces noise and RF interference.
The MIC2182 is available in a 16-pin SOP (small-outline
package) and SSOP (shrink small-outline package) with an
operating range from –40°C to +85°C.
Features
• 4.5V to 32V Input voltage range
• 1.25V to 6V Output voltage range
• 95% efficiency
• 300kHz oscillator frequency
• Current sense blanking
• 5Ω impedance MOSFET Drivers
• Drives N-channel MOSFETs
• 600µA typical quiescent current (skip-mode)
• Logic controlled micropower shutdown (IQ < 0.1µA)
• Current-mode control
• Cycle-by-cycle current limiting
• Built-in undervoltage protection
• Adjustable undervoltage lockout
• Easily synchronizable
• Precision 1.245V reference output
• 0.6% total regulation
• 16-pin SOP and SSOP packages
• Frequency foldback overcurrent protection
• Sustained short-circuit protection at any input voltage
• 20A output current capability
Applications
• DC power distribution systems
• Notebook and subnotebook computers
• PDAs and mobile communicators
• Wireless modems
• Battery-operated equipment
Typical Application
VIN
4.5V to 30V*
R7
100k
GND
C3
0.1µF
C2
2.2nF
MIC2182-3.3BSM
D2
10 VIN
VDD 11 SD103BWS
C5
0.1µF
BST 14
C6
6 EN/UVLO HSD 16
0.1µF
2 PWM
C4
1nF
VSW 15
LSD 13
1 SS
PGND 12
C9
4.7µF
16V
C11
22uf
35V
x2
Q2*
Si4884
L1
10µH
Q1*
Si4884
D1
B140
R2
0.02Ω
3 COMP
R1
2k
5 SYNC
CSH 8
VOUT 9
VREF 7
SGND
4
C13, 1nF
* 30V maximum input voltage limit is due
to standard 30V MOSFET selection.
C1
0.1µF See “Application Information” section for
5V to 3.3V/10A and other circuits.
VOUT
3.3V/4A
C7
220uf
10V ×2
GND
4.5V–30V* to 3.3V/4A Converter
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 22, 2004
1
M9999-042204
1 page  
MIC2182
Micrel
Parameter
Condition
Min Typ Max Units
Reference Output (Fixed Versions Only)
Reference Voltage
1.220 1.245 1.270 V
Reference Line Regulation
Reference Load Regulation
Enable/UVLO
6V < VIN < 32V
0µA < IREF < 100µA
1 mV
2 mV
Enable Input Threshold
0.6 1.1 1.6
V
UVLO Threshold
2.2 2.5 2.8
V
Enable Input Current
Soft Start
VEN/UVLO = 5V
0.1 5 µA
Soft-Start Current
Current Limit
VSS = 0V
–3.5 –5 –6.5 µA
Current-Limit Threshold Voltage
Error Amplifier
VCSH = VOUT
75 100 135 mV
Error Sense Amplifier Gain
20
Current Amp
Current Sense Amplifier Gain
2.0
Oscillator Section
Oscillator Frequency
270 300 330 kHz
Maximum Duty Cycle
86 %
Minimum On-Time
SYNC Threshold Level
VOUT = VOUT(nominal) + 200mV
140 250
ns
0.7 1.3 1.9
V
SYNC Input Current
SYNC Minimum Pulse Width
VSYNC = 5V
0.1 5 µA
200 ns
SYNC Capture Range
Note 6
330 kHz
Frequency Foldback Threshold measured at VOUT pin
0.75 0.95 1.15
V
Foldback Frequency
60 kHz
Gate Drivers
Rise/Fall Time
Output Driver Impedance
CL = 3000pF
source
sink
60 ns
5 8.5
3.5 6
Ω
Ω
Driver Nonoverlap Time
80 ns
PWM Input
PWM Input Current
VPWM = 0V
–10 µA
Note 1.
Note 2.
Note 3.
Note 4.
Note 5.
Note 6.
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
25°C limits are 100% production tested. Limits over the operating temperature range are guaranteed by design and are not production tested.
VIN > 1.3 × VOUT (for the feedback voltage reference and output voltage line and total regulation).
See applications information for limitations on the maximum operating frequency.
April 22, 2004
5
M9999-042204
5 Page 
MIC2182
A block diagram of the MIC2182 PWM current-mode control
loop is shown in Figure 3 and the PWM mode voltage and
current waveforms are shown in figure 5A. The inductor
current is sensed by measuring the voltage across the
resistor, RCS. A ramp is added to the amplified current-sense
signal to provide slope compensation, which is required to
prevent unstable operation at duty cycles greater than 50%.
A transconductance amplifier is used for the error amplifier,
which compares an attenuated sample of the output voltage
with a reference voltage. The output of the error amplifier is
the COMP (compensation) pin, which is compared to the
current-sense waveform in the PWM block. When the current
signal becomes greater than the error signal, the comparator
turns off the high-side drive. The COMP pin (pin 3) provides
access to the output of the error amplifier and allows the use
of external components to stabilize the voltage loop.
Micrel
Skip-Mode Control Loop
This control method is used to improve efficiency at light
output loads. At light output currents, the power drawn by the
MIC2182 is equal to the input voltage times the IC supply
current (IQ). At light output currents, the power dissipated by
the IC can be a significant portion of the total output power,
which lowers the efficiency of the power supply. The MIC2182
draws less supply current in skip mode by disabling portions
of the control and drive circuitry when the IC is not switching.
The disadvantage of this method is greater output voltage
ripple and variable switching frequency.
A block diagram of the MIC2182 skip mode is shown in Figure
4. Skip mode voltage and current waveforms are shown in
figure 5B.
CONTROL LOGIC AND
SKIP-MODE LOGIC
LOW-SIDE DRIVER
ONE SHOT
VDD
Reference VIN
Q
RS
Skip-Mode
Current
Limit
0.07V
VIN
CIN
VDD
11
VIN
10
4.7µF
D2
VBST
14
HSD
16
VSW
CBST
Q2
L1
RCS
15
LSD
13
PGND
12
Q1
VOUT
COUT
ONE SHOT
Low
Comp
LOW
FORCES
PWM MODE
Hysteresis
Comp
±1%
–2%VBG
MIC2182 [adj.] Skip Mode
April 22, 2004
Current
Sense
Amp
AV = 2
CSH
8
VOUT
9
FB
7
VOUT = 1.245V 1+ RR21
R1
R2
Figure 4. Skip-Mode Operation
11
M9999-042204
11 Page | ||
| Páginas | Total 28 Páginas | |
| PDF Descargar | [ Datasheet MIC2182.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MIC2182 | High-Efficiency Synchronous Buck Controller | Micrel Semiconductor |
| MIC2183 | Low Voltage Synchronous Buck PWM Control IC | Micrel Semiconductor |
| MIC2184 | Low Voltage Buck PWM Control IC | Micrel Semiconductor |
| MIC2185 | Low Voltage Synchronous Boost PWM Control IC |  MICREL |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |