module, featuring a unique adaptive ON-time control
architecture. The module incorporates a DC/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 Microchip’s HyperLight Load
®
(HLL) and the MIC45205-2 uses Microchip’s Hyper
Speed Control
®
architecture that 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 0.85 x V
IN
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.
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 Diagram
PVDD
5VDD
V
IN
12V
PG
PVIN
VIN
C
IN
ON
EN
OFF
GND
FREQ
ANODE
BST
RIA
VOUT
V
OUT
UP to 6A
R
FB1
R
FB2
R
LIM
ILIM
PGND
C
OUT
MIC45205
FB
RIB
SW
C
FF
2017 Microchip Technology Inc.
DS20005798A-page 1
MIC45205
Functional Block Diagram
VIN
BST
5VDD
PVDD
EN
FREQ
VDD
VIN
BST
ANODE
PVIN
PVDD
PWM
CONTROLLER
DH
EN
SW
RIB
R
INJ
RIA
C
INJ
SW
VOUT
FREQ
PG
FB
GND
PG
FB
AGND
ILIM
DL
PGND
PGND
ILIM
DS20005798A-page 2
2017 Microchip Technology Inc.
MIC45205
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings †
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 (5V
DD
+ 0.3V)
V
FB
, V
RIB
to PGND ...................................................................................................................... –0.3V to (5V
DD
+ 0.3V)
PGND to GND........................................................................................................................................... –0.3V to +0.3V
Operating Ratings ‡
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 5V
DD
† Notice:
Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of the device at those or any other conditions above those indicated
in the operational sections of this specification is not intended. Exposure to maximum rating conditions for extended
periods may affect device reliability.
‡ Notice:
The device is not guaranteed to function outside its operating ratings.
TABLE 1-1:
ELECTRICAL CHARACTERISTICS
Electrical Characteristics:
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.
Note 1
Parameter
Power Supply Input
Input Voltage Range
Quiescent Supply Current
(MIC45205-1)
Quiescent Supply Current
(MIC45205-2)
Operating Current
Shutdown Supply Current
5V
DD
Output
5V
DD
Output Voltage
5V
DD
UVLO Threshold
5V
DD
UVLO Hysteresis
LDO Load Regulation
Reference
Feedback Reference Voltage
FB Bias Current
Enable Control
EN Logic Level High
EN
HIGH
1.8
—
—
V
—
V
FB
I
FB_BIAS
0.792
0.784
—
0.8
0.8
5
0.808
0.816
500
V
nA
T
J
= +25°C
–40°C
≤
T
J
≤
+125°C
V
FB
= 0.8V
V
DD
UVLO
UVLO_
HYS
V
DD(LR)
4.8
3.8
—
0.6
5.1
4.2
400
2
5.4
4.6
—
3.6
V
V
mV
%
V
IN
= 7V to 26V, I
5VDD
= 10 mA
V
5VDD
rising
V
5VDD
falling
I
5VDD
= 0 mA to 40 mA
V
IN
, PV
IN
I
Q
I
Q
I
IN
I
SHDN
4.5
—
—
—
—
—
0.35
2.1
31
0.1
26
0.75
3
—
10
V
mA
mA
mA
µA
—
V
FB
= 1.5V
V
FB
= 1.5V
V
PVIN
= V
IN
= 12V, V
OUT
= 1.8V,
I
OUT
= 0A
f
SW
= 600 kHz (MIC45205-2)
SW = unconnected, V
EN
= 0V
Symbol
Min.
Typ.
Max.
Units
Conditions
2017 Microchip Technology Inc.
DS20005798A-page 3
MIC45205
TABLE 1-1:
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Characteristics:
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.
Note 1
Parameter
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
Note 1:
T
SHD
T
SHD_
HYS
Symbol
EN
LOW
EN
HYS
I
ENBIAS
Min.
—
—
—
400
—
—
—
140
—
Typ.
—
200
5
600
350
85
0
200
5
Max.
0.6
—
10
750
—
—
—
260
—
Units
V
mV
µA
Conditions
—
—
V
EN
= 12V
V
FREQ
= V
IN
, I
OUT
= 2A
V
FREQ
= 50% V
IN
, I
OUT
= 2A
—
V
FB
= 1V
—
FB from 0V to 0.8V
f
SW
D
MAX
D
MIN
t
OFF(MIN)
t
SS
V
CL_
OFFSET
kHz
%
%
ns
ms
–30
–23
55
25
–14
–7
70
35
0
9
85
45
mV
mV
µA
µA
V
FB
= 0.79V
V
FB
= 0V
V
FB
= 0.79V
V
FB
= 0V
—
—
V
SC
I
CL
I
SC
I
SW_
LEAKAGE
—
—
—
—
10
10
µA
µA
I
FREQ_
LEAK
V
PG_TH
V
PG_HYS
t
PG_DLY
V
PG_LOW
85
—
—
—
—
—
90
6
100
70
160
15
95
—
—
200
—
—
% V
OUT
Sweep V
FB
from Low-to-High
% V
OUT
Sweep V
FB
from High-to-Low
µs
mV
°C
°C
Sweep V
FB
from Low-to-High
V
FB
< 90% × V
NOM
, I
PG
= 1 mA
T
J
rising
—
Specification for packaged product only.
DS20005798A-page 4
2017 Microchip Technology Inc.
MIC45205
TEMPERATURE SPECIFICATIONS (Note
1)
Parameters
Temperature Ranges
Junction Operating Temperature
Range
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature
Package Thermal Resistances
Thermal Resistance QFN-52
Thermal Resistance QFN-52
Note 1:
JA
JC
—
—
21.7
5.0
—
—
°C/W
°C/W
Note 2
Note 2
T
J
—
T
S
—
–40
—
–65
—
—
—
—
—
+125
+150
+150
+260
°C
°C
°C
°C
—
—
—
Soldering, 10s
Sym.
Min.
Typ.
Max.
Units
Conditions
2:
The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable
junction temperature and the thermal resistance from junction to air (i.e., T
A
, T
J
,
JA
). Exceeding the
maximum allowable power dissipation will cause the device operating junction temperature to exceed the
maximum +125°C rating. Sustained junction temperatures above +125°C can impact the device reliability.
θ
JA
and
θ
JC
were measured using the MIC45205 evaluation board.
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