MIC45205-1/-2
26V/6A DC-to-DC Power Module
General Description
Micrel’s MIC45205 is a synchronous step-down regulator
module, featuring a unique adaptive ON-time control
architecture. The module incorporates a DC-to-DC
controller, power MOSFETs, bootstrap diode, bootstrap
capacitor, and an inductor in a single package; simplifying
the design and layout process for the end user.
This highly-integrated solution expedites system design
and improves product time-to-market. The internal
MOSFETs and inductor are optimized to achieve high
efficiency at a low output voltage. The fully-optimized
design can deliver up to 6A current under a wide input
voltage range of 4.5V to 26V, without requiring additional
cooling.
The MIC45205-1 uses Micrel’s HyperLight Load (HLL)
MIC45205-2 uses Micrel’s Hyper Speed Control™
architecture which enables ultra-fast load transient
response, allowing for a reduction of output capacitance.
The MIC45205 offers 1% output accuracy that can be
adjusted from 0.8V to 5.5V with two external resistors.
Additional features include thermal shutdown protection,
input undervoltage lockout, adjustable current limit, and
short circuit protection. The MIC45205 allows for safe
start-up into a pre-biased output.
Datasheet and other support documentation can be found
on Micrel’s web site at:
www.micrel.com.
®
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
No compensation required
Up to 6A output current
>93% peak efficiency
Output voltage: 0.8V to 5.5V with ±1% accuracy
Adjustable switching frequency from 200kHz to 600kHz
Enable input and open-drain power good output
Hyper Speed Control (MIC45205-2) architecture
enables fast transient response
HyperLight Load (MIC45205-1) improves light load
efficiency
Supports safe startup into pre-biased output
CISPR22, Class B compliant
–40°C to +125°C junction temperature range
Thermal-shutdown protection
Short-circuit protection with hiccup mode
Adjustable current limit
Available in 52-pin 8mm × 8mm × 3mm QFN package
Applications
•
•
•
•
High power density point-of-load conversion
Servers, routers, Networking, and base stations
FPGAs, DSP, and low-voltage ASIC power supplies
Industrial and medical equipment
Typical Application
Efficiency (V
IN
= 12V)
vs. Output Current (MIC45205-1)
100
90
80
5.0V
OUT
3.3V
OUT
2.5V
OUT
1.8V
OUT
1.5V
OUT
1.2V
OUT
1.0V
OUT
0.8V
OUT
EFFICIENCY (%)
70
60
50
40
30
20
10
0
1
2
3
4
5
6
7
f
SW
= 600kHz
8
9
OUTPUT CURRENT (A)
Hyper Speed Control is a trademark of Micrel, Inc.
HyperLight Load is a registered trademark of Micrel, 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 21, 2015
Revision 2.0
Micrel, Inc.
MIC45205
Ordering Information
(1)
Part Number
Switching
Frequency
200kHz to 600kHz
200kHz to 600kHz
Features
Junction
Temperature
Range
–40°C to +125°C
–40°C to +125°C
Package
52-pin
8mm × 8mm × 3mm QFN
52-pin
8mm × 8mm × 3mm QFN
Lead
Finish
Pb-Free
Pb-Free
MIC45205-1YMP
MIC45205-2YMP
Note:
Hyper Light Load
Hyper Speed Control
1. Devices are ESD sensitive. Handling precautions are recommended.
Pin Configuration
52-Pin 8mm × 8mm × 3mm QFN
(Top View)
January 21, 2015
2
Revision 2.0
Micrel, Inc.
MIC45205
Pin Description
MIC45205
Pin Number
1
Pin Name
GND
Pin Function
Analog Ground. Connect bottom feedback resistor to GND. GND and PGND should be
connected together at a low impedance point.
Internal +5V Linear Regulator Output. Powered by VIN, 5VDD is the internal supply bus for the
device. In the applications with VIN < +5.5V, 5VDD should be tied to VIN to by-pass the linear
regulator.
PVDD. Supply input for the internal low-side power MOSFET driver.
Power Ground. PGND is the return path for the step-down power module power stage. The
PGND pin connects to the sources of internal low-side power MOSFET, the negative terminals of
input capacitors, and the negative terminals of output capacitors.
The SW pin connects directly to the switch node. Due to the high-speed switching on this pin, the
SW pin should be routed away from sensitive nodes. The SW pin also senses the current by
monitoring the voltage across the low-side MOSFET during OFF time.
Power Input Voltage. Connection to the drain of the internal high side power MOSFET. Connect
an input capacitor from PVIN to PGND.
Output Voltage. Connected to the internal inductor, the output capacitor should be connected
from this pin to PGND as close to the module as possible.
Ripple Injection Pin A. Leave floating, no connection.
Ripple Injection Pin B. Connect this pin to FB.
Anode Bootstrap Diode. Anode connection of internal bootstrap diode, this pin should be
connected to the PVDD pin.
Connection to the internal bootstrap circuitry and high-side power MOSFET drive circuitry.
Connect all three BST pins together.
Feedback. Input to the transconductance amplifier of the control loop. The FB pin is referenced to
0.8V. A resistor divider connecting the feedback to the output is used to set the desired output
voltage. Connect the bottom resistor from FB to GND.
Power Good. Open drain output. If used, connect to an external pull-up resistor of at least
10kohm between PG and the external bias voltage.
Enable. A logic signal to enable or disable the step-down regulator module operation. The EN pin
is TTL/CMOS compatible. Logic high = enable, logic low = disable or shutdown. EN pin has an
internal 1MΩ (typical) pull-down resistor to GND. Do not leave floating
Internal 5V Linear Regulator Input. A 1μF ceramic capacitor from VIN to GND is required for
decoupling.
Switching Frequency Adjust. Use a resistor divider from VIN to GND to program the switching
frequency. Connecting FREQ to VIN sets frequency = 600kHz.
Current Limit. Connect a resistor between ILIM and SW to program the current limit.
Depopulated pin positions.
PVIN Exposed Pad. Internally connected to PVIN pins. Please see
PCB Layout
Recommendations
section.
VOUT Exposed Pad. Internally connected to VOUT pins. Please see
PCB Layout
Recommendations
section.
2, 3
4, 5
6
−
8,
45, 52
10
−
12,
31
−
34
14
−19
21
−
29
36
−
38
39
40, 41
42
−
44
5VDD
PVDD
PGND
SW
PVIN
VOUT
RIA
RIB
ANODE
BST
46
FB
47
PG
48
EN
49
50
51
9, 13,
20, 30, 35
−
−
VIN
FREQ
ILIM
KEEPOUT
PVIN ePAD
VOUT ePAD
January 21, 2015
3
Revision 2.0
Micrel, Inc.
MIC45205
Absolute Maximum Ratings
(2)
V
PVIN
, V
VIN
to PGND .......................................
−0.3V
to +30V
V
PVDD
, V
5VDD
, V
ANODE
to PGND.........................
−0.3V
to +6V
V
SW
, V
FREQ
, V
ILIM
, V
EN
to PGND ............
−0.3V
to (V
IN
+0.3V)
V
BST
to V
SW
........................................................
−0.3V
to 6V
V
BST
to PGND ..................................................
−0.3V
to 36V
V
PG
to PGND ..................................
−0.3V
to (5VDD + 0.3V)
V
FB
, V
RIB
to PGND ..........................
−0.3V
to (5VDD + 0.3V)
PGND to GND ..............................................
−0.3V
to +0.3V
Junction Temperature .............................................. +150°C
Storage Temperature (T
S
) .........................
−65°C
to +150°C
Lead Temperature (soldering, 10s) ............................ 260°C
Operating Ratings
(3)
Supply Voltage (V
PVIN
, V
VIN
) .............................. 4.5V to 26V
Output Current ................................................................. 6A
Enable Input (V
EN
) .................................................. 0V to V
IN
Power Good (V
PG
) ............................................. 0V to 5VDD
Junction Temperature (T
J
) ........................
−40°C
to +125°C
(4)
Junction Thermal Resistance
8mm × 8mm × 3mm QFN-52 (θ
JA
) ................ 21.7°C/W
8mm × 8mm × 3mm QFN-52 (θ
JC
) .................. 5.0°C/W
Electrical Characteristics
(5)
V
IN
= V
EN
= 12V, V
OUT
= 3.3V, V
BST
−
V
SW
= 5V, T
J
= +25ºC.
Bold
values indicate
−40ºC <
T
J
<
+125ºC, unless otherwise noted.
Parameter
Power Supply Input
Input Voltage Range (V
PVIN
, V
IN
)
Quiescent Supply Current
(MIC45205-1)
Quiescent Supply Current
(MIC45205-2)
Operating Current
Shutdown Supply Current
5VDD Output
5VDD Output Voltage
5VDD UVLO Threshold
5VDD UVLO Hysteresis
LDO Load Regulation
Reference
Feedback Reference Voltage
FB Bias Current
Notes:
2. Exceeding the absolute maximum rating may damage the device.
3. The device is not guaranteed to function outside operating range.
4.
θ
JA
and
θ
JC
were measured using the MIC45205 evaluation board.
5. Specification for packaged product only.
Condition
Min.
Typ.
Max.
Units
4.5
V
FB
= 1.5V
V
FB
= 1.5V
V
PVIN
= V
IN
= 12V, V
OUT
= 1.8V, I
OUT
= 0A
f
SW
= 600kHz (MIC45205-2)
SW = unconnected, V
EN
= 0V
0.35
2.1
31
0.1
26
0.75
3
V
mA
mA
mA
10
µA
V
IN
= 7V to 26V, I
5VDD
= 10mA
V
5VDD
rising
V
5VDD
falling
I
5VDD
= 0 to 40mA
4.8
3.8
5.1
4.2
400
5.4
4.6
V
V
mV
0.6
2
3.6
%
T
J
= 25°C
−40°C
≤ T
J
≤ 125°C
V
FB
= 0.8V
0.792
0.784
0.8
0.8
5
0.808
0.816
500
V
nA
January 21, 2015
4
Revision 2.0
Micrel, Inc.
MIC45205
Electrical Characteristics
(5)
(Continued)
V
IN
= V
EN
= 12V, V
OUT
= 3.3V, V
BST
−
V
SW
= 5V, T
J
= +25ºC.
Bold
values indicate
−40ºC <
T
J
<
+125ºC, unless otherwise noted.
Parameter
Enable Control
EN Logic Level High
EN Logic Level Low
EN Hysteresis
EN Bias Current
Oscillator
Switching Frequency
Maximum Duty Cycle
Minimum Duty Cycle
Minimum Off-Time
Soft-Start
Soft-Start Time
Short-Circuit Protection
Current-Limit Threshold
Short-Circuit Threshold
Current-Limit Source Current
Short-Circuit Source Current
Leakage
SW, BST Leakage Current
FREQ Leakage Current
Power Good (PG)
PG Threshold Voltage
PG Hysteresis
PG Delay Time
PG Low Voltage
Thermal Protection
Overtemperature Shutdown
Overtemperature Shutdown Hysteresis
T
J
Rising
160
15
°C
°C
Sweep V
FB
from Low-to-High
Sweep V
FB
from High-to-Low
Sweep V
FB
from Low-to-High
V
FB
< 90% × V
NOM
, I
PG
= 1mA
85
90
6
100
70
200
95
% V
OUT
% V
OUT
µs
mV
10
10
µA
µA
V
FB
= 0.79V
V
FB
= 0V
V
FB
= 0.79V
V
FB
= 0V
−30
−23
55
25
−14
−7
70
35
0
9
85
45
mV
mV
µA
µA
5
ms
V
FB
= 1V
140
V
FREQ
= V
IN
, I
OUT
= 2A
V
FREQ
= 50% V
IN,
I
OUT
= 2A
400
600
350
85
0
200
260
750
kHz
%
%
ns
V
EN
= 12V
200
5
10
1.8
0.6
V
V
mV
µA
Condition
Min.
Typ.
Max.
Units
January 21, 2015
5
Revision 2.0
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