MIC2186
Micrel, Inc.
MIC2186
Low Voltage PWM Control IC
General Description
Micrel’s MIC2186 is a high efficiency boost PWM control IC.
With its wide input voltage range of 2.9V to 14V, the MIC2186
can be used to efficiently boost voltages in 1- or 2-cell Li Ion
battery powered applications, as well as to boost voltages in
fixed 3.3V, 5V, or 12V systems. Its powerful 1.6Ω output
driver allows the MIC2186 to supply large output currents with
the selection of proper external MOSFETs.
The MIC2186 can be configured to operate at 100kHz,
200kHz, or 400kHz. With it’s fixed frequency PWM architec-
ture, and easily synchronized drive, the MIC2186 is ideal for
noise-sensitive telecommunications applications.
MIC2186 also features a low current shutdown mode of
0.5µA and programmable undervoltage lockout. A manually
selectable SKIP Mode allows high efficiencies in light load
situations.
The MIC2186 is available in 16 pin SOIC and QSOP package
options with an operating range from –40°C to 125°C.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Input voltage range: 2.9V to 14V
1.6Ω output driver
Oscillator frequency of 100kHz/200kHz/400kHz
Frequency sync to 600kHz
Front edge blanking
PWM Current Mode Control
Selectable light load SKIP mode
600µA quiescent current (SKIP-Mode)
0.5µA shutdown current
Cycle-by-Cycle current limiting
Frequency foldback protection
Adjustable under-voltage lockout
Precision 1.245V reference output
16 pin SOIC and QSOP package options
Selectable 50% maximum duty cycle for flyback applica-
tions
DC power distribution systems
Wireless Modems
ADSL line cards
SLIC power supplies
1-and 2-cell Li Ion battery operated equipment
Applications
•
•
•
•
•
Ordering Information
Part Number
Standard
Pb-Free
MIC2186BM
MIC2186BQS
MIC2186YM
MIC2186YQS
Frequency (kHz)
100 / 200 / 400
100 / 200 / 400
Voltage
Adj
Adj
Ambient
Temp. Range
–40°C to +125°C
–40°C to +125°C
Package
16-lead SOP
16-lead QSOP
Typical Application
V
IN
= 3.3V
2.2µH
MBR2535CT
V
OUT
= 12V
C
IN
120µF
20V
1
7
13
15
10
4
8
2
11
VINA
EN/UVLO
HIDC
FREQ/2
VDD
COMP
VREF
SKIP
SYNC
SS
3
12V Output Efficiency
VINP
FB
MIC2186
OUTN
CSH
14
9
16
6
C
OUT
150µF(x2)
20V
95
90
EFFICIENCY (%)
85
80
75
70
65
60
0
V
IN
= 3.3V
0.5
1
1.5
2
2.5
OUTPUT CURRENT (A)
3
Si4404DY
(x2)
4.5mΩ
PGND
SGND
5
12
Adjustable Output Boost Converter
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
MIC2186
Micrel, Inc.
Pin Configuration
VINA 1
SKIP 2
SS 3
COMP 4
SGND 5
FB 6
EN/UVLO 7
VREF 8
16 VINP
15 FREQ/2
14 OUTN
13 HIDC
12 PGND
11 SYNC
10 VDD
9 CSH
16-pin Narrow Body SOP (M)
16-pin QSOP (QS)
Pin Description
Pin Number
1
2
Pin Name
VINA
SKIP
Pin Function
Input voltage to control circuitry (2.9V to 14V).
SKIP (Input): Regulator operates in PWM mode (no pulse skipping) when
pin is pulled low, and skip mode when raised to Vdd. There is no automatic
switching between PWM and skip mode available on this device.
Soft start reduces the inrush current and delays and slows the output voltage
rise time. A 5µA current source will charge the capacitor up to Vdd.
Compensation (Output): Internal error amplifier output. Connect to a
capacitor or series RC network to compensate the regulator’s control loop.
Small signal ground: must be routed separately from other grounds to the (-)
terminal of Cout.
Feedback Input - regulates FB to 1.245V.
Enable/Undervoltage Lockout (input): A low level on this pin will power down
the device, reducing the quiescent current to under 0.5µA. This pin has two
separate thresholds, below 1.5V the output switching is disabled, and below
0.9V the device is forced into a complete micropower shutdown. The 1.5V
threshold functions as an accurate undervoltage lockout (UVLO) with 135mV
hysteresis.
The 1.245V reference is available on this pin. A 0.1µF capacitor should be
connected form this pin to SGnd.
The (+) input to the current limit comparator. A built in offset of 100mV
between CSH and SGnd 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 SGND with 1µF. Maximum source current is 0.5mA.
Frequency Synchronization (Input): Connect an external clock signal to
synchronize the oscillator. Leading edge of signal above 1.5V starts switch-
ing cycle. Connect to SGND if not used.
MOSFET driver power ground, connects to the bottom of the current sense
resistor and the (–) terminal of C
IN
.
High Duty Cycle. Sets duty cycle and frequency along with Freq/2. Logic
HIGH sets 85% maximum duty cycle. Logic LOW sets 50% maximum duty
cycle. See applications section for more information.
High current drive for N channel MOSFET. Voltage swing is from ground to
V
IN
. R
ON
is typically 1.6Ω.
Sets duty cycle and frequency along with HiDC. See applications section for
more information.
Power input voltage to the gate drive circuitry (2.9V to 14V). This pin is
normally connected to the output voltage.
3
4
5
6
7
SS
COMP
SGND
FB
EN/UVLO
8
9
VREF
CSH
10
11
VDD
SYNC
12
13
PGND
HIDC
14
15
16
OUTN
FREQ/2
VINP
M9999-042205
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April 2005
MIC2186
Micrel, Inc.
Absolute Maximum Ratings (Note 1)
Supply Voltage (V
IN
A, V
IN
P) ......................................... 15V
Digital Supply Voltage (V
DD
) ........................................... 7V
SKIP Pin Voltage (V
SKIP
) ................................. –0.3V to 7V
Max Duty Cycle Pin Voltage (V
HIDC
) ................ –0.3V to 7V
Frequency Divider Pin Voltage (V
FREQ/2
) ........ –0.3V to 7V
Sync Pin Voltage (V
SYNC
) ................................ –0.3V to 7V
Comp Pin Voltage (V
COMP
) .............................. –0.3V to 3V
Feedback Pin Voltage (V
FB
) ............................ –0.3V to 3V
Enable Pin Voltage (V
EN/UVLO
) ...................... –0.3V to 15V
Current Sense Voltage (V
CSH
) ......................... –0.3V to 1V
Power Dissipation (P
D
)
16 lead SOP .............................. 400mW @ T
A
= 85°C
16 lead QSOP ........................... 245mW @ T
A
= 85°C
Ambient Storage Temp ............................ –65°C to +150°C
ESD Rating (Note 3)
Operating Ratings (Note 2)
Supply Voltage (V
IN
A, V
IN
P) ........................ +2.9V to +14V
Operating Ambient Temperature ......... –40°C
≤
T
A
≤
+85°C
Junction Temperature ....................... –40°C
≤
T
J
≤
+125°C
PackageThermal Resistance
θ
JA
16-lead SOP ............................................... 100°C/W
θ
JA
16-lead QSOP ............................................. 163°C/W
Electrical Characteristics
V
IN
A = 5V, V
IN
P = V
OUT
= 12V, SKIP = 0V, FREQ/2 = 0V, HiDC = 3V, V
CSH
= 0V, T
J
= 25°C, unless otherwise specified.
Bold
values
indicate –40°C < T
J
< +125°C.
Parameter
Regulation
Feedback Voltage Reference
(±1%)
(±2%)
3V
≤
V
IN
A
≤
9V; 0mV
≤
CSH
≤
75mV; (±3%)
Feedback Bias Current
Output Voltage Line Regulation
Output Voltage Load Regulation
Input & V
DD
Supply
V
IN
A Input Current, PWM mode
V
IN
P Input Current, PWM mode
V
IN
A Input Current, SKIP mode
Shutdown Quiescent Current
Digital Supply Voltage (VDD)
Digital Supply Load Regulation
Undervoltage Lockout
V
SKIP
= 0V
V
SKIP
= 0V (excluding external MOSFET gate current)
V
SKIP
= 5V
VEN/UVLO = 0V; (I
VINA
+ I
VINP
)
I
L
= 0
I
L
= 0 to 0.5mA
V
DD
upper threshold (turn on threshold)
V
DD
lower threshold (turn off threshold)
Reference Output (V
REF
)
Reference Voltage
(±1.5%)
(±2.5%)
Reference Voltage Line
Regulation
Reference Voltage Load
Regulation
5V < VinA < 9V
0 < I
REF
< 100µA
1.226
1.213
2
1
1.245
1.264
1.276
V
V
mV
mV
2.9
2.82
0.7
2.8
0.6
0.5
3.0
0.03
2.75
2.65
5
3.18
mA
mA
mA
µA
V
V
V
V
3V
≤
V
IN
A
≤
9V
0mV
≤
CSH
≤
75mV
1.233
1.220
1.208
1.245
50
+0.08
–1.2
1.245
1.258
1.270
1.282
V
V
V
nA
%/V
%
Condition
Min
Typ
Max
Units
April 2005
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M9999-042205
MIC2186
Parameter
Enable/UVLO
Enable Input Threshold
UVLO Threshold
UVLO Hysteresis
Enable Input Current
Soft Start
Soft Start Current
Current Limit
Current Limit Threshold Voltage
Error Amplifier
Error Amplifier Gain
Current Amplifier
Current Amplifier Gain
SKIP Input
SKIP Threshold
SKIP Input Current
HIDC Input
HIDC Threshold
Oscillator Section
Oscillator Frequency (f
O
)
Maximum Duty Cycle
Minimum On Time
FREQ/2 Frequency (f
O
)
Frequency Foldback Threshold
Frequency Foldback Frequency
SYNC Threshold Level
SYNC Input Current
SYNC Minimum Pulse Width
SYNC Capture Range
Gate Drivers
Rise/Fall Time
Output Driver Impedance
C
L
= 3300pF
source; V
IN
P = 12V
sink; V
IN
P = 12V
source; V
IN
P =5V
sink; V
IN
P = 5V
Note 1.
Micrel, Inc.
Condition
Min
Typ
Max
Units
0.6
1.4
0.9
1.5
140
1.2
1.6
V
V
mV
V
EN/UVLO
= 5V
0.2
5
µA
5
µA
(Voltage on CSH to trip current limit)
80
100
120
mV
20
V/V
3.7
V/V
0.6
V
SKIP
= 3V
0.6
1.4
0.1
2.2
5
V
µA
1.4
2.2
V
360
V
FB
= 1.0V, V
HIDC
= 3V
V
FB
= 1.0V, V
HIDC
= 0V
V
FB
= 1.5V, V
HiDC
= 3V
V
HiDC
= 3V, V
FREQ/2
= 3V
Measured on FB
V
HiDC
= 3V, V
FREQ/2
= 0V
0.6
170
400
85
50
180
200
0.3
90
1.4
0.1
440
kHz
%
ns
230
kHz
V
kHz
2.2
5
V
µA
ns
200
Note 4
f
O
+ 15 %
50
1.8
1.6
2.6
2.4
4
3.5
600
kHz
ns
Ω
Ω
Ω
Ω
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 recommended.
See application information for limitations on maximum operating frequency.
Note 2.
Note 3.
Note 4.
M9999-042205
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April 2005
MIC2186
Micrel, Inc.
Typical Characteristics
Quiescent Current vs.
Temperature (SKIP Mode)
0.8
0.7
0.6
I
Q
(mA)
I
Q(PWM)
(mA)
Quiescent Current vs.
Temperature (PWM Mode)
3.65
3.6
3.55
3.5
3.45
3.4
V
IN
A = 5V
DC
V
IN
P = 12V
DC
I
Q
= I
QVINA
+I
QVINP
4
3.5
3
2.5
2
1.5
1
Quiescent Current vs.
Input Voltage(PWM Mode)
400kHz
I
Q(SKIP)
(mA)
0.5
0.4
0.3
0.2
0.1
V
IN
A = 5V
DC
V
IN
P = 12V
DC
I
Q
= I
QVINA
+I
QVINP
200kHz
100kHz
0
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
3.35
-60 -40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
V
IN
P =12V
DC
0.5 I = I
Q
QVINA
+I
QVINP
0
0 2 4 6 8 10 12 14 16
INPUT VOLTAGE (V
INA
)
Quiescent Current vs.
Input Voltage (PWM Mode)
4
3.5
3
I
Q(PWM)
(mA)
I
Q
(mA)
Quiescent Current vs.
Input Voltage (SKIP Mode)
0.9
1.2452
REFERENCE VOLTAGE (V)
Reference Voltage
vs. Input Voltage
V
IN
P = 12V
DC
1.245
1.2448
1.2446
1.2444
1.2442
1.244
0
2
4 6 8 10 12 14 16
INPUT VOLTAGE (V
INA
)
V
IN
P = 12V
0.85
0.8
V
IN
P = 9V
DC
2.5
2
1.5
1
0.5
0
0
2
V
IN
P = 9V
0.75
0.7
0.65
0.6
0.55
0.5
0
V
IN
P = 5V
DC
V
IN
P = 5V
I
Q
= I
QVINA
+ I
QVINP
f
S
= 400kHz
4 6 8 10 12 14 16
INPUT VOLTAGE (V
INA
)
V
IN
P = 12V
DC
2
4 6 8 10 12 14 16
INPUT VOLTAGE (V
INA
)
Reference Voltage
vs. Reference Current
1.2451
REFERENCE VOLTAGE (V)
REFERENCE VOLTAGE (V)
Reference Voltage
vs. Temperature
1.2454
1.2452
1.2450
1.2448
1.2446
1.2444
1.2442
1.2440
1.2438
1.2436
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
VDD (V)
VDD vs.
Input Voltage
3.10
3.05
3.00
2.95
2.90
2.85
V
IN
P = 12V
DC
2.80
0
2 4
6 8 10 12 14
INPUT VOLTAGE (V
INA
)
1.245
1.2449
1.2448
1.2447
1.2446
1.2445
1.2444
1.2443
0
V
IN
P = 12V
DC
V
IN
A = 5V
DC
V
IN
P = 12V
DC
V
IN
A = 5V
DC
20 40 60 80 100 120
REFERENCE CURRENT (µA)
VDD vs.
Load Current
3.035
3.030
3.025
VDD (V)
VDD vs.
Temperature
3.08
3.06 V A = 5V
IN
DC
3.04
VDD (V)
Ienable vs.
Venable
300
V
IN
P = 12V
DC
–40°C
250 V
IN
A = 5V
DC
IENABLE (µA)
V
IN
P = 12V
DC
V
IN
A = 5V
DC
V
IN
P = 12V
DC
3.020
3.015
3.010
3.005
3.000
2.995
0
0.2
0.4 0.6 0.8
IVDD (mA)
1
1.2
200
150
100
50
0
0
2
4
6 8 10 12 14
VENABLE (V)
20°C
85°C
3.02
3.00
2.98
2.96
2.94
-60 -40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
April 2005
5
M9999-042205
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