Micrel MIC2207 User Manual
MIC2207
3mmx3mm 2MHz 3A PWM Buck
Regulator
General Description
The Micrel MIC2207 is a high efficiency PWM buck
(step-down) regulators that provides up to 3A of
output current. The MIC2207 operates at 2MHz and
has proprietary internal compensation that allows a
closed loop bandwidth of over 200KHz.
The low on-resistance internal p-channel MOSFET
of the MIC2207 allows efficiencies over 94%,
reduces external components count and eliminates
the need for an expensive current sense resistor.
The MIC2207 operates from 2.7V to 5.5V input and
the output can be adjusted down to 1V. The devices
can operate with a maximum duty cycle of 100% for
use in low-dropout conditions.
The MIC2207 is available in the exposed pad 3mm x
3mm MLF-12L package with a junction operating
range from –40°C to +125°C.
Features
• 2.7 to 5.5V supply voltage
• 2MHz PWM mode
• Output current to 3A
• >94% efficiency
• 100% maximum duty cycle
• Adjustable output voltage option down to 1V
• Ultra-fast transient response
• Ultra-small external components
Stable with a 1µH inductor and a 4.7µF
output capacitor
• Fully integrated 3A MOSFET switch
• Micropower shutdown
• Thermal shutdown and current limit
protection
• Pb-free 3mm x 3mm MLF-12L package
• –40°C to +125°C junction temperature range
Applications
• 5V or 3.3V Point of Load Conversion
• Telecom/Networking Equipment
• Set Top Boxes
• Storage Equipment
• Video Cards
____________________________________________________________________________________________________
Typical Application
MIC2207
Efficiency
3.3V
96
MIC2207
3A 2MHz Buck Regulator
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
94
92
90
88
86
EFFICIENCY (%)
84
82
80
OUT
4.5V
IN
5V
IN
5.5V
IN
00.511.522.53
OUTPUT CURRENT (A)
M9999-040705
www.micrel.com
Micrel MIC2207
Ordering Information
Part Number
MIC2207YML Adj. –40° to +125°C 3x3 MLF-12L Pb-free
Note:
1. Other Voltage options available. Contact Micrel for details.
Output
Voltage
(1)
Pin Configuration
SW
1
VIN
2
PGND
SGND
3
4
BIAS EN
5
67
FB NC
3mm x 3mm MLF-12 (ML)
Pin Description
Pin Number Pin Name Pin Function
1,12 SW Switch (Output): Internal power P-Channel MOSFET output switch
2,11 VIN
3,10 PGND Power Ground. Provides the ground return path for the high-side drive current.
4 SGND
5 BIAS
6 FB
7 NC
8 EN
9 PGOOD
EP GND Connect to ground.
Supply Voltage (Input): Supply voltage for the source of the internal P-channel
MOSFET and driver.
Requires bypass capacitor to GND.
Signal (Analog) Ground. Provides return path for control circuitry and internal
reference.
Internal circuit bias supply. Must be bypassed with a 0.1uF ceramic capacitor to
SGND.
Feedback. Input to the error amplifier, connect to the external resistor divider
network to set the output voltage.
No Connect. Not internally connected to die. This pin can be tied to any other pin
if desired.
Enable (Input). Logic level low will shutdown the device, reducing the current
draw to less than 5uA.
Power Good. Open drain output that is pulled to ground when the output voltage
is within +/- 7.5% of the set regulation voltage
Junction Temp. Range Package Lead Finish
12
SW
11
VIN
10
PGND
9
PGOOD
8
EP
April 2005 2
M9999-040705
www.micrel.com
Micrel MIC2207
Absolute Maximum Ratings
(1)
Supply Voltage (VIN) ............................................ +6V
Output Switch Voltage (V
Output Switch Current (I
Logic Input Voltage (V
Storage Temperature (Ts)................ -60°C to +150°C
ESD Rating
(3)
........................................................2kV
Electrical Characteristics
) ............................... +6V
SW
) ................................. 11A
SW
)......................... -0.3V to V
EN
(4)
IN
Operating Ratings
Supply Voltage (VIN)............................+2.7V to +5.5V
Logic Input Voltage (V
Junction Temperature (TJ) .............. –40°C to +125°C
Junction Thermal Resistance
3x3 MLF-12L (θ
(2)
) ............................. 0V to V
EN
) ................................... 60°C/W
JA
IN
VIN = VEN = 3.6V; L = 1µH; C
= 4.7µF; TA = 25°C, unless noted.
OUT
Bold
values indicate –40°C< TJ < +125°C
Parameter Condition Min Typ Max Units
Supply Voltage Range
Under-Voltage Lockout
(turn-on)
2.7
2.45
2.55
5.5
2.65
V
V
Threshold
UVLO Hysteresis 100 mV
Quiescent Current VFB = 0.9 * V
(not switching) 570
NOM
Shutdown Current VEN = 0V 2
[Adjustable] Feedback
Voltage
±
1% I
±
2% (over temperature) I
LOAD
= 100mA
LOAD
= 100mA
0.99
0.98
1
900
10
1.01
1.02
µA
µA
V
FB pin input current 1 nA
Current Limit in PWM Mode VFB = 0.9 * V
Output Voltage Line
Regulation
Output Voltage Load
V
> 2V; VIN = V
OUT
< 2V; VIN = 2.7V to 5.5V; I
V
OUT
20mA < I
LOAD
NOM
+500mV to 5.5V; I
OUT
LOAD
LOAD
= 100mA
= 100mA
3.5
5
0.07 %
< 3A 0.2 0.5 %
A
Regulation
Maximum Duty Cycle
PWM Switch ONResistance
V
≤ 0.4V
FB
= 50mA VFB = 0.7V
I
SW
(High Side Switch)
FB_NOM
Oscillator Frequency
Enable Threshold
Enable Hysteresis
Enable Input Current 0.1
100
%
95 200
1.8
0.5
2
0.85
50
300
2.2
1.3
2
Ω
m
MHz
V
mV
µA
Power Good Range ±7 ±10 %
Power Good Resistance I
Over-Temperature
= 500µA 145
PGOOD
160
200
Ω
°
C
Shutdown
Over-Temperature
20
°
C
Hysteresis
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model: 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
5. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value that is initially
measured at a 1V differential. For outputs below 2.7V, the dropout voltage is the input-to-output voltage differential with a minimum
input voltage of 2.7V.
April 2005 3
M9999-040705
www.micrel.com
Micrel MIC2207
Typical Characteristics
MIC2207
Efficiency
3.3V
96
94
92
90
88
86
EFFICIENCY (%)
84
82
80
00.511.522.53
OUT
4.5V
IN
5V
IN
5.5V
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
1.8V
95
93
91
89
87
85
83
81
EFFICIENCY (%)
79
77
75
00.511.522.53
OUT
3V
IN
3.3V
IN
3.6V
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
1.5V
85
83
81
79
77
75
73
71
EFFICIENCY (%)
69
67
65
00.511.522.53
OUT
4.5V
IN
5V
5.5V
IN
IN
OUTPUT CURRENT (A)
MIC2207
1V
Efficiency
85
83
81
79
77
75
73
71
EFFICIENCY (%)
69
67
65
OUT
3V
IN
3.3V
IN
3.6V
IN
00.511.522.53
OUTPUT CURRENT (A)
100
98
96
94
92
90
88
86
EFFICIENCY (%)
84
82
80
00.511.522.53
90
88
86
84
82
80
78
76
EFFICIENCY (%)
74
72
70
00.511.522.53
90
88
86
84
82
80
78
76
EFFICIENCY (%)
74
72
70
00.511.522.53
85
80
75
70
EFFICIENCY (%)
65
60
00.511.522.53
MIC2207
Efficiency
2.5V
OUT
3V
IN
3.3V
IN
3.6V
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
1.8V
OUT
4.5V
IN
5V
5.5V
IN
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
1.2V
OUT
3V
IN
3.3V
IN
3.6V
IN
OUTPUT CURRENT (A)
MIC2207
1V
Efficiency
OUT
4.5V
IN
5V
5.5V
IN
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
2.5V
94
92
90
88
86
84
EFFICIENCY (%)
82
80
00.511.522.53
OUT
4.5V
IN
5.5V
5V
IN
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
1.5V
95
90
85
80
EFFICIENCY (%)
75
70
00.511.522.53
OUT
3V
IN
3.3V
IN
3.6V
IN
OUTPUT CURRENT (A)
MIC2207
Efficiency
1.2V
85
83
81
79
77
75
73
71
EFFICIENCY (%)
69
67
65
00.511.522.53
1.010
1.005
1.000
0.995
OUTPUT VOLTAGE (V)
0.990
00.511.522.53
OUT
4.5V
IN
5V
5.5V
IN
IN
OUTPUT CURRENT (A)
Load Regulation
V
= 3.3V
IN
OUTPUT CURRENT (A)
April 2005 4
M9999-040705
www.micrel.com
Micrel MIC2207
Typical Characteristics cont.
SUPPLY VOLTAGE (V)
Feedback Voltage
vs. Supply Voltage
1.2
1
0.8
0.6
0.4
0.2
FEEDBACK VOLTAGE (V)
0
012345
SUPPLY VOLTAGE (V)
160
140
120
(mOhm)
100
DSON
P-CHANNEL R
vs. Temperature
80
60
40
20
3.3V
IN
0
-40
-20
TEMPERATURE (°C)
0
R
DSON
204060
VEN = V
Feedback Voltage
1.010
1.008
1.006
1.004
1.002
1.000
0.998
0.996
0.994
FEEDBACK VOLTAGE (V)
0.992
0.990
vs. Temperature
VIN = 3.3V
0
-40
204060
-20
TEMPERATURE (°C)
2.500
2.400
2.300
2.200
2.100
2.000
1.900
1.800
FREQUENCY (MHz)
1.700
1.600
80
100
120
1.500
Quiescent Current
vs. Supply Voltage
900
800
700
600
500
400
300
200
100
IN
QUIESCENT CURRENT (µA)
0
012345
SUPPLY VOLTAGE (V)
VEN = V
IN
120
115
110
105
(mOhm)
100
DSON
95
90
85
80
75
P-CHANNEL R
70
2.7 3.2 3.7 4.2 4.7 5.2
Enable Threshold
vs. Supply Voltage
1.2
1.0
0.8
0.6
0.4
0.2
ENABLE THRESHOLD (V)
0
80
100
120
2.7 3.2 3.7 4.2 4.7
SUPPLY VOLTAGE (V)
1.2
1.0
0.8
0.6
0.4
0.2
ENABLE THRESHOLD (V)
0
Frequency
vs. Temperature
VIN = 3.3V
0
-40
204060
-20
TEMPERATURE (°C)
R
DSON
vs. Supply Voltage
SUPPLY VOLTAGE (V)
Enable Threshold
vs. Temperature
3.3V
IN
0
-40
204060
-20
TEMPERATURE (°C)
80
100
120
80
100
120
April 2005 5
M9999-040705
www.micrel.com
Micrel MIC2207
Functional Diagram
VIN
VIN
P-Channel
Current Limit
BIAS
HSD
PWM
Control
SW
SW
Bias,
UVLO,
Thermal
Shutdown
MIC2207 Block Diagram
Soft
Start
EA
1.0V
1.0V
FB
PGOOD
PGND
EN
Enable and
Control Logic
SGND
April 2005 6
M9999-040705
www.micrel.com
Loading...