MIC2619
1.2MHz PWM Boost Converter
with OVP
General Description
The MIC2619 is a 1.2MHz pulse width modulated (PWM)
step-up switching regulator that is optimized for low power,
high output voltage applications. With a maximum output
voltage of 35V, and a switch current of over 350mA, the
MIC2619 can easily supply most high voltage bias
applications, such as TV tuners.
The MIC2619 implements a constant frequency 1.2MHz
PWM current-mode control scheme. The high frequency
PWM operation saves board space by reducing external
component sizes. The additional benefit of the constant
frequency PWM control scheme as opposed to variable
frequency control schemes is lower output noise and
smaller input ripple injected back to the battery source.
The MIC2619 has programmable overvoltage protection to
ensure output protection in case of fault condition.
The MIC2619 is available in a low profile Thin SOT-23 6-
pin package. The MIC2619 has a junction temperature
range of –40°C to +125°C.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
•
•
•
2.8V to 6.5V Input Voltage
350mA Switch Current
Output Voltage up to 35V
1.2MHz PWM Operation
1.265V Feedback Voltage
Programmable Over-Voltage Protection (OVP)
<1% Line Regulation
<1µA Shutdown Current
Over-Temperature Protection
Under-Voltage Lock Out (UVLO)
Low Profile Thin SOT-23-6 Package
–40°C to +125°C Junction Temperature Range
Applications
•
Bias Supply Applications:
-
Tuner Varactor Bias
-
High Voltage Bias Supplies
-
Avalanche Photo Diode
-
High Voltage Display Bias
•
DSL/Broadband applications
•
Constant Current Power Supplies
_________________________________________________________________________________________________________________________
Typical Application
1.2MHz Boost Converter with OVP in Thin SOT-23-6
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
March 2010
M9999-030410-A
Micrel, Inc.
MIC2619
Ordering Information
Part Number
MIC2619YD6
Note:
1. Under bar( ) symbol may not be to scale.
Marking
(1)
2619
Overvoltage
Protection
Programmable
Junction Temp.
Range
-40°C to +125°C
Package
Thin SOT-23-6
Lead Finish
Lead Free
Pin Configuration
6-Pin TSOT-23 (YD6)
Pin Description
Pin Number
1
2
3
4
5
6
Pin Name
SW
GND
FB
EN
OVP
VIN
Pin Function
Switch Node (Input): Internal power bipolar collector.
Ground.
Feedback (Input): Output voltage sense node. Connect external resistor network to set
output voltage. Nominal feedback voltage is 1.265V.
Enable (Input): Logic high enables regulator. Logic low shuts down regulator. Do not
leave floating.
Over-Voltage Protection (Input): Programmable to 35V, adjustable through resistor divider
network.
Supply (Input): 2.8V to 6.5V for internal circuitry. Requires a minimum 1.0µF ceramic
capacitor.
March 2010
2
M9999-030410-A
Micrel, Inc.
MIC2619
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) .........................................................7V
Switch Voltage (V
SW
)....................................... –0.3V to 40V
Enable Pin Voltage (V
EN
)..................................... –0.3 to V
IN
Feedback Voltage (V
FB
), (V
OVP
)........................................6V
Ambient Storage Temperature (T
S
)...........–65°C to +150°C
ESD Rating
(3)
................................................................. 2kV
Operating Ratings
(2)
Supply Voltage (V
IN
)......................................... 2.8V to 6.5V
Output Voltage (V
OUT
) .......................................... V
IN
to 35V
Junction Temperature Range (T
J
)............. –40°C to +125°C
Package Thermal Impedance
Thin SOT-23-6 (θ
JA
).........................................177°C/W
Electrical Characteristics
(4)
T
A
= 25°C, V
IN
= V
EN
= 3.6V, V
OUT
= 10V, I
OUT
= 10mA, unless otherwise noted.
Bold
values indicate –40°C
≤
T
J
≤125°C.
Parameter
Supply Voltage Range
Under Voltage Lockout
Quiescent Current
Shutdown Current
Feedback Voltage
Feedback Input Current
Line Regulation
Load Regulation
Maximum Duty Cycle
Switch Current Limit
Switch Saturation Voltage
Switch Leakage Current
Enable Threshold
Condition
Min
2.8
1.8
Typ
Max
6.5
Units
V
V
mA
µA
V
nA
2.1
2.1
0.04
2.4
5
1
1.303
V
FB
> 1.265V, (not switching)
V
EN
= 0V
1.227
1.265
-450
0.2
0.3
V
FB
= 1.265V
2.8V
≤
V
IN
≤
6.5V
5mA
≤
I
OUT
≤
20mA
85
1
%
%
%
mA
90
V
IN
= 3.6V
(5)
V
IN
= 3.6V, I
SW
= 300mA
V
EN
= 0V, V
SW
= 10V
TURN ON
TURN OFF
350
400
0.01
1.5
0.4
14
1.2
1.202
1.265
–200
150
1.328
40
1
mV
µA
V
µA
MHz
V
nA
°C
°C
Enable Pin Current
Oscillator Frequency
Overvoltage Protection
OVP Input Current
Overtemperature Threshold
Shutdown
Notes:
V
EN
= 6.5V
V
OVP
= 1.265V
Hysteresis
10
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 maximum allowable power dissipation will result in excessive
die temperature, and the regulator will go into thermal shutdown.
2. This device is not guaranteed to operate beyond its specified operating ratings.
3. Devices are inherently ESD sensitive. Handling precautions required. Human body model: 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
5. Guaranteed by design.
March 2010
3
M9999-030410-A
Micrel, Inc.
MIC2619
Typical Characteristics
Efficiency V
OUT
= 5V
100%
90%
80%
EFFICIENCY (%)
EFFICIENCY (%)
90%
80%
70%
Efficiency V
OUT
= 10V
90%
80%
70%
EFFICIENCY (%)
V
IN
=5V
V
IN
=3.3V
Efficiency V
OUT
= 12V
70%
60%
50%
40%
30%
20%
10%
0%
0
50
100
150
LOAD CURR ENT (mA)
200
L = 10µH
C = 1µF
V
IN
=3.6V
V
IN
=3V
V
IN
=4.2V
60%
50%
40%
30%
20%
10%
0%
0
20
40
60%
50%
40%
30%
20%
10%
0%
L = 10µH
C = 1µF
V
IN
=5V
V
IN
=3.3V
L = 10µH
C = 1µF
60
80
100
0
LOAD CURRENT (mA)
20
40
60
LOAD CUR RENT (mA)
80
Efficiency V
OUT
= 35V
70%
60%
EFFICIENCY (%)
50%
40%
30%
20%
10%
0%
0
4
8
12
LOAD CURRENT (mA)
16
L = 10µH
C = 1µF
V
IN
=6.5V
V
IN
=5V
Load Regulation (V
OUT
=10V)
10.10
10.08
OUTPUT VOLTAGE (V)
OUTPU T VOLTAGE (V)
10.06
10.04
10.02
10.00
9.98
9.96
9.94
9.92
9.90
0
10 20 30 40 50 60
LOAD CURR ENT (mA)
70
V
IN
= 3.6V
L = 10µH
C = 1µF
Load Regulation (V
OUT
=35V)
35.5
35.4
35.3
35.2
35.1
35.0
34.9
34.8
34.7
34.6
34.5
0
2
4
6
8
10
LOAD CURR ENT (mA)
12
V
IN
= 5V
L = 10µH
C = 1µF
Line Regulation (V
OUT
=12V)
12.20
12.16
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
35.5
35.4
35.2
35.1
35.0
34.9
34.8
34.7
34.6
34.5
35.3
Line Regulation (V
OUT
=35V)
1.50
1.45
1.40
1.35
1.30
1.25
1.20
1.15
1.10
1.05
1.00
0.95
0.90
3
3.5
Frequency
vs. Input Voltage
12.12
12.08
12.04
12.00
11.96
11.92
11.88
11.84
11.80
3
3.5
4 4.5 5 5.5 6
INPUT VOLTAGE (V)
6.5
I
OU T
= 40mA
L = 10µH
C = 1µF
FREQUENCY (MHz)
I
OU T
= 10mA
L = 10µH
C = 1µF
V
OU T
= 12V
L = 10µH
C = 1µF
I
LOAD
= 40mA
4.5
4.9
5.3
5.7
6.1
INPUT VOLTAGE (V)
6.5
4 4.5 5 5.5 6
INPUT VOLTAGE (V)
6.5
Switch Current Limit
vs. Input Voltage
1100
1000
CU RRENT LIMIT (mA)
C URRENT LIMIT (mA)
900
800
700
600
500
400
300
200
100
0
Switch Current Limit
vs. T emperature
3.50
3.25
3.00
2.75
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
Quiescent Current
vs. Input Voltage
900
800
700
600
500
400
300
200
3
3.5
4 4.5 5 5.5 6
IN PU T VOLTAGE (V)
6.5
V
OU T
= 12V
L = 10µH
C = 1µF
V
IN
= 3.6V
V
OU T
= 12V
L = 10µH
C = 1µF
QUIESCENT CURRENT (mA)
V
F B
= 3V
No Switching
-40 -20
0
20 40 60 80 100 120
TEMPERATUR E (°C)
3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5
INPUT VOLTAGE (V)
March 2010
4
M9999-030410-A
Micrel, Inc.
MIC2619
Typical Characteristics
(Continued)
Feedback Voltage
vs. T emperature
1.34
SWITCHING FREQUENCY (M Hz)
Switching Frequency
vs. T emperature
1.40
1.35
1.30
1.25
1.20
1.15
1.10
1.05
1.00
0.95
0.90
-40 -20
V
IN
= 3.6V
V
OU T
= 12V
I
OU T
= 25mA
L = 10µH
C = 1µF
1.32
FEEDB ACK VOLTAGE (V)
1.30
1.28
1.26
1.24
1.22
1.20
1.18
-40 -20
0 20 40 60 80 100 120
TEMPER ATURE (°C)
V
IN
= 3.6V
V
OU T
= 12V
I
OU T
= 25mA
L = 10µH
C = 1µF
0 20 40 60 80 100 120
Temperature (°C)
March 2010
5
M9999-030410-A