Operating Temperature Range ........................... -40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) ................................. +300°C
Soldering Temperature (reflow) ....................................... +260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Package Thermal Characteristics
(Note 1)
TQFN
Junction-to-Ambient Thermal Resistance (θ
JA
) ..........30°C/W
Junction-to-Case Thermal Resistance (θ
JC
) .................2°C/W
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to
www.maximintegrated.com/thermal-tutorial.
V
SUP
= V
SUPSW
= 14V, V
EN
= 14V, L1 = 2.2µH, C
IN
= 4.7µF, C
OUT
= 44µF, C
BIAS
= 2.2µF, C
BST
= 0.1µF, R
FOSC
= 12kΩ, T
A
= T
J
=
-40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.
PARAMETER
Supply Voltage
Transient Event Supply Voltage
Supply Current (3.3V)
Supply Current (5V)
Shutdown Supply Current
BIAS Regulator Voltage
BIAS Undervoltage Lockout
BIAS Undervoltage-Lockout
Hysteresis
Thermal-Shutdown Threshold
Thermal-Shutdown Threshold
Hysteresis
OUTPUT VOLTAGE
PWM-Mode Output Voltage
(Note 3)
PFM-Mode Output Voltage
(Note 4)
PWM-Mode Output Voltage
(Note 3)
V
OUT_5V
V
OUT_
PFM_5V
V
OUT_3.3V
V
FB
= V
BIAS
, 6V < V
SUPSW
< 36V,
fixed-frequency mode
No load, V
FB
= V
BIAS
, PFM mode
V
F
B = V
BIA
S, 6V < V
SUPS
W < 36V,
fixed-frequency mode
4.9
4.9
3.23
5
5
3.3
5.1
5.15
3.37
V
V
V
SYMBOL
V
SUP
,
V
SUPSW
V
SUP_LD
STANDBY
STANDBY
Electrical Characteristics
CONDITIONS
MIN
3.5
TYP
MAX
36
42
UNITS
V
V
µA
µA
µA
V
V
mV
°C
°C
t
LD
< 1s
Standby mode, no load, V
OUT
= 3.3V,
V
FSYNC
= 0V
Standby mode, no load, V
OUT
= 5V,
V
FSYNC
= 0V
V
E
N = 0V
V
SUP
= V
SUPSW
= 6V to 42V. I
BIA
S = 0
to 10mA
V
BIAS
rising
4.7
2.9
15
20
5
5
3.15
400
175
15
I
SUP_
I
SUP_
30
35
10
5.4
3.4
500
I
SHDN
V
BIAS
V
UVBIAS
www.maximintegrated.com
Maxim Integrated
│
3
MAX17242/MAX17243
3.5V–36V, 2A/3A, Synchronous Buck Converter
with 15µA Quiescent Current and Reduced EMI
Electrical Characteristics (continued)
V
SUP
= V
SUPSW
= 14V, VEN = 14V, L1 = 2.2µH, C
IN
= 4.7µF, C
OUT
= 44µF, C
BIAS
= 2.2µF, C
BST
= 0.1µF, R
FOSC
= 12kΩ, T
A
= T
J
=
-40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.
PARAMETER
PFM-Mode Output Voltage
(Note 4)
Load Regulation
Line Regulation
BST Input Current
I
BST_ON
I
BST_OFF
LX Current Limit
LX Rise Time
Spread Spectrum
High-Side Switch On-
Resistance
High-Side Switch Leakage
Current
Low-Side Switch On-
Resistance
Low-Side Switch Leakage
Current
FB Input Current
FB Regulation Voltage
FB Line Regulation
Transconductance (from FB to
COMP)
Minimum On-Time
Maximum Duty Cycle
Oscillator Frequency
SYNC, EN, AND SPS LOGIC THRESHOLDS
External Input Clock Acquisition
time
External Input Clock Frequency
External Input Clock High
Threshold
External Input Clock Low
Threshold
FSYNC Leakage Current
Soft-Start Time
t
SS
t
FSYN
C
R
FOSC
= 12kΩ (Note 5)
V
FSYNC_HI
V
FSYN
C rising
V
FSYNC_LO
V
FSYN
C falling
T
A
= +25°C
5.6
8
1.8
1.4
0.4
1
12
1
2.6
Cycle
MHz
V
V
µA
ms
I
FB
V
FB
∆V
LINE
gm
t
ON_MIN
DC
MAX
R
FOSC
= 73.2kΩ
R
FOSC
= 12kΩ
2.0
98
400
2.2
2.4
R
ON_L
R
ON_H
I
LX
SYMBOL
PFM_3.3V
CONDITIONS
No load, V
FB
= V
BIAS
, PFM mode
V
FB
= V
BIAS
, 30mA < I
LOA
D < 3A
V
FB
= V
BIAS
, 6V < V
SUPSW
< 36V
High-side MOSFET on,
V
BST
- V
LX
= 5V
High-side MOSFET off,
V
BST
- V
LX
= 5V
MAX17243
MAX17242
V
OUT
= 5V, 3.3V
Spread spectrum enabled
I
LX
= 0.5A, V
BIA
S = 5V
High-side MOSFET off, V
SU
P = 36V,
V
LX
= 0V, T
A
= +25°C
I
LX
= 0.5A, V
BIA
S = 5V
Low-side MOSFET off, V
SUP
= 36V,
V
LX
= 36V, T
A
= +25°C
T
A
= +25°C
FB connected to an external resistive
divider, 6V < V
SUPSW
< 36V
6V < V
SUPSW
< 36V
V
FB
= 1V, V
BIAS
= 5V
MIN
3.23
TYP
3.3
0.5
0.02
1.5
1.5
MAX
3.4
UNITS
V
%
%/V
mA
µA
V
OUT_
3.75
2.5
5
3.33
4
FOSC
±3%
60
1
35
1
20
6.25
4.16
A
ns
140
5
70
5
100
1.01
mΩ
µA
mΩ
µA
nA
V
%/V
µS
0.99
1
0.02
700
80
99
ns
%
kHz
MHz
www.maximintegrated.com
Maxim Integrated
│
4
MAX17242/MAX17243
3.5V–36V, 2A/3A, Synchronous Buck Converter
with 15µA Quiescent Current and Reduced EMI
Electrical Characteristics (continued)
V
SUP
= V
SUPSW
= 14V, V
EN
= 14V, L1 = 2.2µH, C
IN
= 4.7µF, C
OUT
= 44µF, C
BIAS
= 2.2µF, C
BST
= 0.1µF, R
FOSC
= 12kΩ, T
A
= T
J
=
-40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.
PARAMETER
Enable Input High Threshold
Enable Input Low Threshold
Enable Threshold-Voltage
Hysteresis
Enable Input Current
Spread-Spectrum Input High
Threshold
Spread-Spectrum Input Low
Threshold
Spread-Spectrum Input Current
SYMBOL
V
EN_HI
V
EN_LO
V
EN_HYS
I
EN
V
SPS_HI
V
SPS_LO
I
SPS
V
RISING
V
FALLING
T
A
= +25°C
V
FB
rising, V
PGOOD
= high
V
FB
falling, V
PGOOD
= low
I
SINK
= 5mA
V
OUT
in regulation, T
A
= +25°C
V
OUT
rising (Monitor FB pin)
V
OUT
falling (Monitor FB pin)
107
104
93
90
0.1
95
92.5
25
0.4
1
T
A
= +25°C
2.0
0.4
1
97
95
0.2
0.1
1
CONDITIONS
MIN
2.4
0.6
TYP
MAX
UNITS
V
V
V
µA
V
V
µA
POWER-GOOD AND OVERVOLTAGE-PROTECTION THRESOLDS
PGOOD Switching Level
PGOOD Debounce Time
PGOOD Output Low Voltage
PGOOD Leakage Current
Overvoltage Protection
Threshold
Note
Note
Note
Note
2:
3:
4:
5:
%V
FB
µs
V
µA
%
Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by design.
Device not in dropout condition.
Guaranteed by design; not production tested.
Contact the factory for SYNC frequency outside the specified range.
京公网安备 11010802033920号
EEWORLD
