MIC2193
Micrel
MIC2193
400kHz SO-8 Synchronous Buck Control IC
General Description
Micrel’s MIC2193 is a high efficiency, PWM synchronous
buck control IC housed in the SO-8 package. Its 2.9V to 14V
input voltage range allows it to efficiently step down voltages
in 3.3V, 5V, and 12V systems as well as 1- or 2-cell Li Ion
battery powered applications.
The MIC2193 solution saves valuable board space. The
device is housed in the space-saving SO-8 package, whose
low pin-count minimizes external components. Its 400kHz
PWM operation allows a small inductor and small output
capacitors to be used. The MIC2193 can implement all-
ceramic capacitor solutions.
The MIC2193 drives a high-side P-channel MOSFET, elimi-
nating the need for high-side boot-strap circuitry. This feature
allows the MIC2193 to achieve maximum duty cycles of
100%, which can be useful in low headroom applications. A
low output driver impedance of 4Ω allows the MIC2193 to
drive large external MOSFETs to generate a wide range of
output currents.
The MIC2193 is available in an 8 pin SOIC package with a
junction temperature range of –40°C to +125°C.
Features
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2.9V to 14V input voltage range
400kHz oscillator frequency
PWM current mode control
100% maximum duty cycle
Front edge blanking
4Ω output drivers
Cycle-by-cycle current limiting
Frequency foldback short circuit protection
8 lead SOIC package
Point of load power supplies
Distributed power systems
Wireless Modems
ADSL line cards
Servers
Step down conversion in 3.3V, 5V, and 12V systems
1-and 2-cell Li Ion battery operated equipment
Applications
Typical Application
V
IN
3.3V
120µF
6.3V
(×2)
2k
1µF
2.2nF
0.012Ω
MIC2193BM
VIN
VDD
CS
OUTP
Si9803
(×2)
3.8µH
Si9804
(×2)
10k
22.6k
V
OUT
1.8V, 5A
220µF
6.3V
(×2)
COMP OUTN
GND
FB
Adjustable Output Synchronous Buck 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 2004
1
M9999-042704
MIC2193
Micrel
Ordering Information
Part Number
MIC2193BM
MIC2193YM
Voltage
Adjustable
Adjustable
Frequency
400KHz
400KHz
Temperature Range
–40°C to +125°C
–40°C to +125°C
Package
8-lead SOP
8-lead SOP
Lead Finish
Standard
Pb-Free
Pin Configuration
VIN 1
COMP 2
FB 3
CS 4
8 OUTP
7 OUTN
6 GND
5 VDD
8 Lead SOIC (M)
Pin Description
Pin Number
1
2
3
4
Pin Name
VIN
COMP
FB
CS
Pin Function
Controller supply voltage. Also the (+) input to the current sense amp.
Compensation (Output): Internal error amplifier output. Connect to a
capacitor or series RC network to compensate the regulator’s control loop.
Feedback Input: The circuit regulates this pin to 1.245V.
The (–) input to the current limit comparator. A built in offset of 110mV
between VIN and CSL in conjunction with the current sense resistor sets the
current limit threshold level. This is also the (–) input to the current amplifier.
3V internal linear-regulator output. VDD is also the supply voltage bus for the
chip. Bypass to GND with 1µF.
Ground.
High current drive for the synchronous N-channel MOSFET. Voltage swing
is from ground to VIN. On-resistance is typically 6Ω at 5V
IN
.
High current drive for the high side P-channel MOSFET. Voltage swing is
from ground to VIN. On-resistance is typically 6Ω at 5V
IN
.
5
6
7
8
VDD
GND
OUTN
OUTP
M9999-042704
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April 2004
MIC2193
Micrel
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
IN
) ..................................................... 15V
Digital Supply Voltage (V
DD
) ........................................... 7V
Comp Pin Voltage (V
COMP
) ............................ –0.3V to +3V
Feedback Pin Voltage (V
FB
) .......................... –0.3V to +3V
Current Sense Voltage (V
IN
– V
CS
) ................ –0.3V to +1V
Power Dissipation (P
D
) ..................... 285mW @ T
A
= 85°C
Ambient Storage Temp ............................ –65°C to +150°C
ESD Rating
Note 3 .......................................................
2kV
Operating Ratings
(Note 2)
Supply Voltage (V
IN
) .................................... +2.9V to +14V
Junction Temperature ....................... –40°C
≤
T
J
≤
+125°C
Package Thermal Resistance
θ
JA
8-lead SOP ................................................. 140°C/W
Electrical Characteristics
V
IN
= 5V, V
OUT
= 3.3V, T
J
= 25°C, unless otherwise specified.
Bold
values indicate –40°C<T
J
<+125°C.
Parameter
Regulation
Feedback Voltage Reference
Feedback Bias Current
Output Voltage Line Regulation
Output Voltage Load Regulation
Output Voltage Total Regulation
Input & V
DD
Supply
V
IN
Input Current (I
Q
)
Digital Supply Voltage (V
DD
)
Digital Supply Load Regulation
Undervoltage Lockout
UVLO Hysteresis
Current Limit
Current Limit Threshold Voltage
Error Amplifier
Error Amplifier Gain
Current Amplifier
Current Amplifier Gain
Oscillator Section
Oscillator Frequency (f
O
)
Maximum Duty Cycle
Minimum On Time
Frequency Foldback Threshold
Frequency Foldback Frequency
V
FB
= 1.0V
V
FB
= 1.5V
Measured on FB
360
100
165
0.3
90
400
440
kHz
%
ns
V
kHz
3.0
V/V
20
V/V
V
IN
– V
CS
voltage to trip current limit
90
110
130
mV
(excluding external MOSFET gate current)
I
L
= 0
I
L
= 0 to 1mA
V
DD
upper threshold (turn on threshold)
2.82
1
3.0
0.1
2.65
100
2
3.18
mA
V
V
V
mV
5V
≤
V
IN
≤12V
0mV < (V
IN
– V
CS
) < 75mV
5V
≤V
IN
≤12V,
0mV < (V
IN
– V
CS
) < 75mV (±3%)
1.208
(1%)
(2%)
1.233
1.22
1.245
1.245
50
0.09
0.9
1.282
1.257
1.27
V
V
nA
%/V
%
V
Condition
Min
Typ
Max
Units
April 2004
3
M9999-042704
MIC2193
Parameter
Gate Drivers
Rise/Fall Time
Output Driver Impedance
C
L
= 3300pF
Source, V
IN
= 12V
Sink, V
IN
= 12V
Source, V
IN
= 5V
Sink, V
IN
= 5V
V
IN
= 12V
V
IN
= 5V
V
IN
= 3.3V
50
4
4
6
6
50
80
160
10
10
12
12
Condition
Min
Typ
Max
Micrel
Units
ns
Ω
Ω
Ω
Ω
ns
ns
ns
Driver Non-overlap Time
Note 1.
Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when
operating the device outside of its operating ratings. The maximum allowable power dissipation is a function of the maximum junction
temperature, T
J(Max)
, the junction-to-ambient thermal resistance,
θ
JA
, and the ambient temperature, T
A
.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive, handling precautions required. Human body model, 1.5kΩ in series with 100pF.
Note 2.
Note 3.
M9999-042704
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April 2004
MIC2193
Micrel
Typical Characteristics
Quiescent Current
vs. Supply Voltage
6
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
Quiescent Current
vs. Temperature
2.0
1.8
1.6
1.4
V
DD
(V)
3.15
3.10
3.05
3.00
2.95
2.90
V
IN
= 5V
2.85
2.80
0
V
DD
vs. Input Voltage
5
4
3
2
1
0
0
5
10
SUPPLY VOLTAGE (V)
15
1.2
1.0
0.8
0.6
0.4
0.2
0
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
5
10
INPUT VOLTAGE (V)
15
3.06
3.04
V
DD
(V)
3.02
3.00
2.98
2.96
2.94
2.92
2.90
0
V
IN
= 12V
VDD (V)
3.30
3.20
3.10
3.00
2.90
2.80
2.70
2.60
V
IN
= 5V
2.50
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
3.10
3.08
V
DD
vs. Load
3.50
3.40
V
DD
vs. Temperature
Reference Voltage
vs. Temperature
1.300
1.290
1.280
1.270
1.260
1.250
1.240
1.230
1.220
1.210
1.200
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
V
IN
= 5V
V
IN
= 5V
V
IN
= 3.3V
0.2 0.4 0.6 0.8
1
1.2
V
DD
LOAD CURRENT (mA)
CURRENT LIMIT THRESHOLD (mV)
Switching Frequency
vs. Input Voltage
2.5
5
FREQUENCY VARIATION (%)
0
-5
-10
-15
Switching Frequency
vs. Temperature
Overcurrent Threshold
vs. Input Voltage
130
125
120
115
110
105
100
95
90
0
2 4 6 8 10 12 14
INPUT VOLTAGE (V)
FREQUENCY VARIATION (%)
2.0
1.5
1.0
0.5
0
-0.5
-1.0
-1.5
-2.0
0
5
10
INPUT VOLTAGE (V)
15
V
IN
= 5V
-20
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
Current Limit Threshold
vs. Temperature
CURRENT LIMIT THREHOLD (mV)
120
115
110
105
100
95
90
85
80
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (°C)
V
IN
= 5V
IMPEDANCE (Ω)
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
0
OUTN Drive Impedance
vs. Input Voltage
14
12
IMPEDANCE (Ω)
10
8
6
4
OUTN Drive Impedance vs.
Input Voltage
Sink (Ω)
Source (Ω)
Source (Ω)
Sink (Ω)
2
4 6 8 10 12 14
INPUT VOLTAGE (V)
2
0
0
5
10
INPUT VOLTAGE (V)
15
April 2004
5
M9999-042704
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