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Buck Converter. MIC2199 Datasheet |
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Micrel, Inc.
MIC2199
MIC2199
300kHz 4mm × 4mm Synchronous Buck Converter
General Description
The MIC2199 is a high-power 300kHz synchronous buck
DC-to-DC controller housed in a small 4mm × 4mm MLF™
12-pin package. The MIC2199 operates from a wide 4.5V
to 32V input and can be programmed for output voltages
from 0.8V to 6V. The wide input voltage capability makes
the MIC2199 an ideal solution for point-of-load DC-to-DC
conversion in 5V, 12V, 24V, and 28V systems.
The 300kHz switching frequency allows the use of a small
inductor and small output capacitors. The current mode PWM
control along with the external COMP pin allows for ease of
stability compensation and fast transient response across a
wide range of applications.
An all N-Channel synchronous architecture and powerful
output drivers allow up to 20A of output current capability.
For smaller external components, refer to the 500kHz
MIC2198.
The MIC2199 is available in a 12-pin 4mm × 4mm MLF™
package with a junction temperature range from –40°C to
125°C.
Features
• 4.5V to 32V input range
• 4mm × 4mm MLF™ package
• 300kHz PWM operation
• 95% efficiency
• Output voltage adjustable down to 0.8V
• 20A output current capability
• Drives all N-Channel MOSFETs
• Logic controlled micropower shutdown
• Cycle-by-cycle current limiting
• Adjustable undervoltage lockout
• Frequency foldback overcurrent protection
Applications
• Point-of-load DC-to-DC conversion from 5V, 12V,
24V, 28V supplies
• Telecom equipment
• Wireless modems
• Servers
• Base stations
Typical Application
4.5VVtoIN 24V
22µF
2kΩ
2.2nF
U1 MIC2199BML
VIN VDD
SD103BWS
4.7µF
EN/UVLO
BST
HSD
VSW
LSD
0.1µF
IRF7821
2µH
IRF7821
COMP
CSH
VOUT
1nF
GND
FB
0.01Ω
3.V3VOU/7T A
220µF
10kΩ
6.04kΩ
4.5V–24V to 3.3V/7A Converter
100.0
95.0
90.0
85.00
VOUT = 3.3V
2 46
ILOAD (A)
8
Efficiency for
VIN = 5V and VOUT = 3.3V
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
January 2010
1 M9999-011310
|
Micrel, Inc.
Ordering Information
Part Number
Standard
Pb-Free
MIC2199BML MIC2199YML
Voltage
Adj
Temperature Range
−40ºC to +125ºC
Package
12-Pin 4x4 MLF®
MIC2199.
Pin Configuration
COMP
EN/UVLO
FB
CSH
VOUT
VIN
1
2
3
4
5
6
12 HSD
11 VSW
10 BST
9 GND
8 LSD
7 VDD
12-Pin 4×4 MLF® (ML)
Pin Description
Pin Number
1
2
Pin Name
COMP
EN/UVLO
3
4
FB
CSH
5
6
7
8
9
10
11
12
VOUT
VIN
VDD
LSD
GND
BST
VSW
HSD
Pin Function
Compensation (Output): Internal error amplifier output. Connect to capacitor
or series RC network to compensate the regulator control loop.
Enable/Undervoltage Lockout (Input): Low-level signal powers down the
controller. Input below the 2.5V threshold disables switching and functions as
an accurate undervoltage lockout (UVLO). Input below the threshold forces
complete micropower (<0.1µA) shutdown.
Feedback (Input): Regulates FB pin to 0.8V. See “Applications Information”
for resistor divider calculations.
Current-Sense High (Input): Current limit comparator non-inverting input. A
built-in offset of 100mV between CSH and VOUT pins in conjunction with the
current-sense resistor set the current limit threshold level. This is also the
non-inverting input to the current sense amplifier.
Current-Sense Low (Input): Output voltage feedback input and inverting
input for the current limit comparator and the current sense amplifier.
Unregulated Input (Input): +4.5V to +32V supply input.
5V Internal Linear-Regulator (Output): VDD is the external MOSFET gate
drive supply voltage and internal supply bus for the IC. Bypass to GND with
4.7µF.
Low-Side Drive (Output): High-current driver output for low-side N-Channel
MOSFET. Voltage swing is between ground and VDD.
Ground (Return).
Boost (Input): Provides drive voltage for the high-side MOSFET driver. The
drive voltage is higher than the input voltage by VDD minus a diode drop.
Switch (Return): High-side MOSFET driver return.
High-Side Drive (Output): High-current driver output for high-side MOSFET.
This node voltage swing is between ground and VIN +5V minus a diode drop.
January 2010
2 M9999-011310
|
Micrel, Inc.
Absolute Maximum Ratings (Note 1)
Analog Supply Voltage (VIN)........................................ +34V
Digital Supply Voltage (VDD).......................................... +7V
Driver Supply Voltage (BST)....................................VIN + 7V
Sense Voltage (VOUT, CSH)................................7V to –0.3V
Enable Pin Voltage (VEN/UVLO)....................................... VIN
Power Dissipation (PD)
4×4 MLF™...................................665mW @ TA = 85°C
Ambient Storage Temperature (TS)........... –65°C to +150°C
ESD, Note 3
MIC2199
Operating Ratings (Note 2)
Analog Supply Voltage (VIN)......................... +4.5V to +32V
Output Voltage Range (VOUT) ........................ +0.8V to +6V
Junction Temperature (TJ)......................... –40°C to +125°C
Package Thermal Resistance
4×4 MLF-12L (θJA)............................................... 60°C/W
Electrical Characteristics (Note 4)
VIN = VEN = 12V; TJ = 25°C, unless noted, bold values indicate –40°C ≤ TJ ≤ +125°C
Parameter
Condition
Min Typ Max
Feedback Voltage Reference
(±1%)
0.792 0.8 0.808
Feedback Voltage Reference
(±2%)
0.784 0.816
Feedback Voltage Reference
Feedback Bias Current
4.5V < VIN < 32V, 0 < (VCSH – VOUT) < 60mV (±3%)
0.776
10
0.824
Output Voltage Range
0.8
6
Output Voltage Line Regulation
Output Voltage Load Regulation
Input and VDD Supply
Quiescent Current
VIN = 4.5V to 32V, VCSH – VOUT = 60mV
25mV < (VCSH – VOUT) < 60mV
excluding external MOSFET gate drive current
0.03
0.5
1.6 2.5
Shutdown Quiescent Current
Digital Supply Voltage (VDD)
Undervoltage Lockout
Enable/UVLO
VEN/UVLO = 0V
IL = 0mA to 5mA
4.7
VIN upper threshold (turn-on threshold)
VIN lower threshold (turn-off threshold)
3.95
0.1 5
5.0 5.3
4.25 4.4
4.1
Enable Input Threshold
0.6 1.1 1.6
UVLO Threshold
2.2 2.5 2.8
Enable Input Current
Current Limit
VEN/UVLO = 5V
0.1 5
Current Limit Threshold Voltage
Error Amplifier
(VCSH – VOUT)
55 75 95
Transconductance Error Amplifier GM
0.2
Oscillator Section
Oscillator Frequency
270 300 330
Maximum Duty Cycle
80 85
Minimum On-Time
170 200
Frequency Foldback Threshold measured at VOUT pin
0.25
Foldback Frequency
0.40 0.55
75
Gate Drivers
Rise/Fall Time
Output Driver Impedance
CL = 3000pF
source
60
5 8.5
sink
3.5 6
Driver Non-Overlap Time
80
Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. Devices are ESD protected; however, handling precautions are recommended. Human body model, 1.5k in series with 100pF.
Note 4. Specification for packaged product only.
Units
V
V
V
nA
V
%/V
%
mA
µA
V
V
V
V
V
µA
mV
mS
kHz
%
ns
V
kHz
ns
Ω
Ω
ns
January 2010
3 M9999-011310
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