Operating Temperature Range ........................ -40NC to +125NC
Junction Temperature .....................................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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)
QSOP
Junction-to-Ambient Thermal Resistance (q
JA
) .....103.7°C/W
Junction-to-Case Thermal Resistance (q
JC
) ...............37°C/W
QSOP-EP
Junction-to-Ambient Thermal Resistance (q
JA
) ..........44°C/W
Junction-to-Case Thermal Resistance (q
JC
) .................6°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.
ELECTRICAL CHARACTERISTICS
(V
SUP
= V
SUPSW
= 14V, V
EN
= 14V, L1 = 22FH, C
IN
= 4.7FF, C
OUT
= 100FF, C
BIAS
= 1FF, C
BST
= 0.1FF, C
CRES
= 1nF, R
FOSC
=
61.9kI, T
A
= T
J
= -40NC to +125NC, unless otherwise noted. Typical values are at T
A
= +25NC.)
PARAMETER
Supply Voltage
Supply Current
Shutdown Supply Current
BIAS Regulator Voltage
BIAS Undervoltage Lockout
BIAS Undervoltage Hysteresis
Thermal-Shutdown Threshold
Thermal-Shutdown Threshold
Hysteresis
OUTPUT VOLTAGE (OUT)
Normal operation, V
FB
= V
BIAS
, I
LOAD
= 1A,
T
A
= +25°C
Normal operation, V
FB
= V
BIAS
, I
LOAD
= 1A,
-40°C
P
T
A
P
+125°C
V
OUT
= 5V, V
FB
= V
BIAS,
30mA < I
LOAD
< 1A
6V < V
SUP
< 28V
4.95
4.9
4.9
5
5
5.05
0.3
0.02
5.05
V
5.1
5.2
V
%
%/V
2
SYMBOL
V
SUP
,
V
SUPSW
I
SUP
CONDITIONS
Normal operation
Normal operation, no switching
Skip mode, no load, V
OUT
= 5V
V
EN
= 0V
V
SUP
= V
SUPSW
= 6V to 42V, V
OUT
< 3V or
V
OUT
> 5.5V, I
LOAD
= 0A (Note 2)
V
BIAS
rising
MIN
3.5
TYP
MAX
28
UNITS
V
mA
FA
FA
2.9
45
9
4.7
2.95
5.0
3.15
550
+175
+15
5.3
3.35
V
BIAS
V
UVBIAS
V
V
mV
NC
NC
Output Voltage
V
OUT
Skip-Mode Output Voltage
Load Regulation
Line Regulation
Maxim Integrated
V
OUT_SKIP
No load, V
FB
= V
BIAS
(Note 3)
*The
parametric values (min, typ, max limits) shown in the Electrical Characteristics table supersede values quoted elsewhere in this data sheet.
MAX16975
28V, 1.2A Automotive Step-Down Converter
with Low Operating Current
ELECTRICAL CHARACTERISTICS* (continued)
(V
SUP
= V
SUPSW
= 14V, V
EN
= 14V, L1 = 22FH, C
IN
= 4.7FF, C
OUT
= 100FF, C
BIAS
= 1FF, C
BST
= 0.1FF, C
CRES
= 1nF, R
FOSC
=
61.9kI, T
A
= T
J
= -40NC to +125NC, unless otherwise noted. Typical values are at T
A
= +25NC.)
PARAMETER
BST Input Current
LX Current Limit
Skip-Mode Current Threshold
Power-Switch On-Resistance
LX Leakage Current
FB Input Current
SYMBOL
I
BST
I
LX
I
SKIP_TH
R
ON
I
LX,LEAK
I
FB
V
FB
FB connected to an external resistive divider,
T
A
= +25°C
FB connected to an external resistive divider,
-40°C
P
T
A
P
+125°C
4.5V < V
SUP
< 28V
V
FB
= 1V, V
BIAS
= 5V
0.99
0.985
R
ON
measured between SUPSW and LX, I
LX
=
1A, V
SUP
= 4.5V to 28V, V
BST
- V
LX
= 4.5V
V
SUPSW
= 28V, V
LX
= 0V, T
A
= +25°C
CONDITIONS
V
BST
- V
LX
= 5V
V
SUP
= 4.5V to 28V, V
SUPSW
= 14V,
T
A
= +25°C
V
SUP
= 4.5V to 28V, V
SUPSW
= 14V
1.5
1.5
MIN
TYP
1.7
1.8
1.8
200
300
0.01
20
1.0
1.0
0.02
1000
110
94
R
FOSC
= 25.5kI, V
SUP
= 4.5V to 28V
Oscillator Frequency
Oscillator Frequency Range
EXTERNAL CLOCK INPUT (FSYNC)
External Input Clock Acquisition
Time
External Input Clock Frequency
t
FSYNC
(Note 3)
f
OSC
+
10%
1.4
0.4
500
f
SW
= 400kHz
f
SW
= 1.0MHz
4
1.6
0.8
1
Cycles
Hz
V
V
kI
ms
ms
V
f
OSC
R
FOSC
= 61.9kI, V
SUP
= 4.5V to 28V
R
FOSC
= 120kI, V
SUP
= 4.5V to 28V (Note 3)
(Note 3)
348
191
220
1.0
400
220
452
249
1000
1.01
V
1.015
%/V
FS
ns
%
MHz
kHz
kHz
kHz
550
1
mA
mI
FA
nA
MAX
2.5
2.0
UNITS
mA
A
TRANSCONDUCTANCE AMPLIFIER (COMP)
FB Regulation Voltage
FB Line Regulation
Transconductance (from FB to
COMP)
Minimum On-Time
Cold-Crank Event Duty Cycle
OSCILLATOR FREQUENCY
DV
LINE
g
m
t
ON
DC
CC
External Input Clock High Threshold V
FSYNC_HI
V
FSYNC
rising
External Input Clock Low Threshold V
FSYNC_LO
V
FSYNC
falling
FSYNC Pulldown Resistance
Soft-Start Time
ENABLE INPUT (EN)
Enable On Threshold Voltage Low
V
EN_LO
R
FSYNC
t
SS
Maxim Integrated
*The
parametric values (min, typ, max limits) shown in the Electrical Characteristics table supersede values quoted elsewhere in this data sheet.
3
MAX16975
28V, 1.2A Automotive Step-Down Converter
with Low Operating Current
ELECTRICAL CHARACTERISTICS* (continued)
(V
SUP
= V
SUPSW
= 14V, V
EN
= 14V, L1 = 22FH, C
IN
= 4.7FF, C
OUT
= 100FF, C
BIAS
= 1FF, C
BST
= 0.1FF, C
CRES
= 1nF, R
FOSC
=
61.9kI, T
A
= T
J
= -40NC to +125NC, unless otherwise noted. Typical values are at T
A
= +25NC.)
PARAMETER
Enable On Threshold Voltage High
Enable Threshold Voltage
Hysteresis
Enable Input Current
RESET
Reset Internal Switching Level
RESETI Threshold Voltage
CRES Threshold Voltage
CRES Threshold Hysteresis
RESETI Input Current
CRES Source Current
CRES Pulldown Current
RES
Output Low Voltage
RES
Leakage Current (Open-
Drain Output)
Reset Debounce Time
t
RES_DEB
V
TH_RISING
V
FB
rising, V
RESETI
= 0V
V
TH_FALLING
V
FB
falling, V
RESETI
= 0V
V
RESETI_HI
V
RESETI
falling
V
CRES_HI
V
CRES_HYS
I
RESET
I
CRES
I
CRES_PD
V
RESETI
= 0V
V
OUT
in regulation
V
OUT
out of regulation
I
SINK
= 5mA
V
OUT
in regulation
V
RESETI
falling
T
A
= +25°C
T
A
= +125°C
20
25
9.5
1
0.4
1
V
CRES
rising
93
91
1.05
1.07
95
93
1.25
1.13
0.05
0.02
10
10.5
96.5
95
1.4
1.19
%V
FB
V
V
V
FA
FA
mA
V
FA
nA
Fs
SYMBOL
V
EN_HI
V
EN,HYS
I
EN
CONDITIONS
MIN
2.2
0.2
10
TYP
MAX
UNITS
V
V
nA
Note 2:
When 3V < V
OUT
< 5.5V, the bias regulator is connected to the output to save quiescent current, V
BIAS
= V
OUT
.
Note 3:
Guaranteed by design; not production tested.
Maxim Integrated
*The
parametric values (min, typ, max limits) shown in the Electrical Characteristics table supersede values quoted elsewhere in this data sheet.
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