EVALUATION KIT AVAILABLE
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Applications
●● Multimedia Power Supply
PINPACKAGE
TEMP RANGE
-40°C to +125°C 32 TQFN-EP*
T3255-4
MAX15011ATJ+
-40°C to +125°C 32 TQFN-EP*
T3255-4
+Denotes a lead(Pb)-free/RoHS-compliant package.
For tape and reel, add a T after “+.”
*EP = Exposed pad.
EN_SW
Pin Configurations
24
23
22
21
20
19
18
17
TOP VIEW
HOLD 25
16
EN_LDO
N.C. 26
15
FB_LDO
OUT_SW 27
14
N.C.
OUT_SW 28
13
SOURCE
12
GATE
MAX15009
N.C. 29
N.C. 30
N.C. 31
*EP
+
1
2
3
4
5
6
7
8
N.C.
N.C.
N.C.
N.C.
SGND
PGND
RESET
N.C.
N.C. 32
*EP = EXPOSED PAD
Typical Operating Circuits and Selector Guide appear at
end of data sheet.
19-0923; Rev 2; 11/14
PKG
CODE
MAX15009ATJ+
EN_PROT
The MAX15009/MAX15011 are available in a thermally
enhanced, 32-pin (5mm x 5mm), TQFN package and
are fully specified over the -40°C to +125°C automotive
operating temperature range.
PART
IN
The MAX15009 OVP controller operates with an external
enhancement mode n-channel MOSFET. While the monitored voltage remains below the adjustable threshold, the
MOSFET stays on. When the monitored voltage exceeds
the OVP threshold, the OVP controller quickly turns off the
external MOSFET. The OVP controller is configurable as
a load-disconnect switch or a voltage limiter.
Ordering Information
IN
The switched output of the MAX15009/MAX15011
incorporates a low RDS(ON) (0.28Ω, typ) pass transistor
switch internally connected to the output of the LDO regulator. This switch features accurate current-limit sensing
circuitry and is capable of controlling remote loads. The
MAX15009/MAX15011 feature an adjustable current limit
and a programmable delay timer to set the overcurrent
detection blanking time of the switch and autoretry timeout.
●● 300mA LDO Regulator, Switched Output, and OVP
Controller (MAX15009)
●● 300mA LDO Regulator and Switched Output
(MAX15011)
●● 5V to 40V Wide Operating Supply Voltage Range
●● 45V Load Dump Protection
●● 67μA Quiescent Current LDO Regulator
●● OVP Controller Disconnects or Limits Output Voltage
During Battery Overvoltage Conditions
●● LDO Regulator with Enable, Hold, and Reset
Features
●● Internal 0.28Ω (typ) n-Channel Switch for Switched
Output
●● 100mA Switched Output with Adjustable Current-Limit
Blanking/Autoretry Delay
OUT_LDO
The 300mA LDO regulator consumes 67μA quiescent
current at light loads and is well suited to power
battery applications. The LDO features independent
enable and hold inputs, as well as a microprocessor (μP)
reset output with adjustable reset timeout period.
Features
OUT_LDO
The MAX15009 includes a 300mA LDO regulator, a
switched output, and an overvoltage protection (OVP)
controller to protect downstream circuits from high|voltage load dump. The MAX15011 includes only the
300mA LDO regulator and switched output. Both devices
operate over a wide supply voltage range from 5V to 40V
and are able to withstand load-dump transients up to
45V. The MAX15009/MAX15011 feature short-circuit and
thermal-shutdown protection.
OC_DELAY
General Description
ILIM
MAX15009/MAX15011
11
N.C.
10
FB_PROT
9
CT
TQFN
(5mm x 5mm)
Pin Configurations continued at end of data sheet.
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Absolute Maximum Ratings
(All pins referenced to SGND, unless otherwise noted.)
IN, GATE.................................................................-0.3V to +45V
EN_LDO, EN_SW, EN_PROT......................-0.3V to (VIN + 0.3V)
SOURCE......................................................-0.3V to (VIN + 0.3V)
OUT_LDO, FB_LDO, FB_PROT, RESET,
OC_DELAY.........................................................-0.3V to +12V
GATE to SOURCE ..................................................-0.3V to +12V
OUT_SW, ILIM, HOLD......................-0.3V to (VOUT_LDO + 0.3V)
OUT_SW to OUT_LDO...........................................-12V to +0.3V
CT to SGND............................................................-0.3V to +12V
SGND to PGND.....................................................-0.3V to +0.3V
IN, OUT_LDO Current.......................................................700mA
OUT_SW Current..............................................................350mA
Current Sink/Source (all remaining pins) ............................50mA
Continuous Power Dissipation (TA = +70°C)
32-Pin TQFN (derate 34.5mW/°C above +70°C)............2.7W*
Thermal Resistance
θJA.............................................................................29.0°C/W
θJC...............................................................................1.7°C/W
Operating Temperature Range...........................-40°C to +125°C
Junction Temperature........................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s)...................................+300°C
*As per JEDEC 51 Standard, Multilayer Board (PCB).
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.
Electrical Characteristics
(VIN = +14V, VSGND = VPGND = 0V, CGATE = 6000pF, CIN = 10μF (ESR < 1.5Ω), COUT_LDO = 22μF (ceramic), COUT_SW = 1μF,
VOUT_LDO = 5V, CT = open, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
SYMBOL
VIN
CONDITIONS
VIN ≥ VOUT + 1.5V
MAX15009
Supply Current
IIN
MAX15011
5
MAX
UNITS
40
V
67
85
EN_LDO = EN_SW = IN,
EN_PROT = 0V, LDO
ON, IOUT_LDO = 100µA,
switch on, IOUT_SW = 0µA,
protector off, measured
from SGND
290
360
EN_LDO = EN_SW =
EN_PROT = IN, LDO
ON, IOUT_LDO = 100µA,
switch on, IOUT_SW = 0µA,
protector on, measured
from SGND
360
500
EN_LDO = EN_SW = IN,
LDO ON, IOUT_LDO =
100µA, switch on, IOUT_
SW = 0µA, measured from
SGND
268
360
16
30
ISHDN
IN Undervoltage Lockout
VUVLO
VIN falling, GATE disabled
IN Undervoltage Lockout
Hysteresis
VUVLO_HYST
www.maximintegrated.com
TYP
EN_LDO = IN, EN_SW =
EN_PROT = 0V, IOUT_LDO
= 0µA, LDO on, switch off,
protector off, measured
from SGND
TA = -40°C to
EN_LDO = EN_SW =
+85°C
EN_PROT = SGND,
T = -40°C to
measured from SGND A
+125°C
Shutdown Supply Current
MIN
µA
µA
40
4.10
4.27
260
4.45
V
mV
Maxim Integrated │ 2
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Electrical Characteristics (continued)
(VIN = +14V, VSGND = VPGND = 0V, CGATE = 6000pF, CIN = 10μF (ESR < 1.5Ω), COUT_LDO = 22μF (ceramic), COUT_SW = 1μF,
VOUT_LDO = 5V, CT = open, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Thermal-Shutdown
Temperature
TSHDN
+160
°C
Thermal Hysteresis
THYST
20
°C
LDO
Output Voltage
FB_LDO Set-Point Voltage
Dual ModeK FB_LDO
Threshold
FB_LDO Input Current
VOUT_LDO
VFB_LDO
VFB_LDO_TH
IFB_LDO
ILOAD = 1mA, FB_LDO = SGND
4.92
5.00
5.09
ILOAD = 300mA, VIN = 8V,
FB_LDO = SGND
4.88
5.00
5.11
With respect to SGND, ILOAD = 1mA,
VOUT_LDO = 5V, adjustable output
option
1.21
1.235
1.26
FB_LDO rising
0.125
FB_LDO falling
0.064
VFB_LDO = 1V
+100
nA
11.0
V
LDO Dropout Voltage
VDO
LDO Output Current
IOUT_LDO
(Note 4)
300
LDO Output Current Limit
ILIM_LDO
OUT_LDO = SGND, VIN = 6V
330
OUT_LDO Load Regulation
OUT_LDO Power-Supply
Rejection Ratio
OUT_LDO Startup Delay
Time
DVOUT/
DIOUT
PSRR
V
1.8
VLDO_ADJ
OUT_LDO Line Regulation
ILOAD = 300mA (Note 3)
800
1500
ILOAD = 200mA (Note 3)
520
1000
700
6V ≤ VIN ≤ 40V, ILOAD = 1mA,
VOUT_LDO = 5V
0.03
0.2
6V ≤ VIN ≤ 40V, ILOAD = 1mA,
FB_LDO = SGND, VOUT_LDO = 3.3V
0.03
0.1
6V ≤ VIN ≤ 40V, ILOAD = 20mA,
FB_LDO = SGND, VOUT_LDO = 5V
0.27
1
6V ≤ VIN ≤ 40V, ILOAD = 20mA,
VOUT_LDO = 3.3V
0.27
0.5
1mA to 300mA, VIN = 8V,
FB_LDO = SGND
0.054
0.15
1mA to 300mA, VIN = 6.3V,
VOUT_LDO = 3.3V
0.038
0.100
IOUT_LDO = 0mA, from EN_LDO rising
tSTARTUP_DELAY to 10% of VOUT_LDO (nominal),
FB_LDO = SGND
mV
mA
500
ILOAD = 10mA, f = 100Hz, 500mVP-P,
VOUT_LDO = 5V
V
-100
LDO Output Voltage
DVOUT/
DVIN
Adjustable output option (Note 2)
V
mA
mV/V
mV/mA
60
dB
30
µs
Dual Mode is a trademark of Maxim Integrated Products, Inc.
www.maximintegrated.com
Maxim Integrated │ 3
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Electrical Characteristics (continued)
(VIN = +14V, VSGND = VPGND = 0V, CGATE = 6000pF, CIN = 10μF (ESR < 1.5Ω), COUT_LDO = 22μF (ceramic), COUT_SW = 1μF,
VOUT_LDO = 5V, CT = open, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
OUT_LDO Overvoltage
Protection Threshold
VOV_TH
OUT_LDO Overvoltage
Protection Sink Current
IOV
CONDITIONS
MIN
1mA sink from OUT_LDO
VOUT_LDO = VOUT (nominal) x 1.15
8
TYP
MAX
UNITS
105
110
%VOUT_LDO
19
mA
ENABLE/HOLD INPUTS
EN_LDO to EN_PROT
Input Threshold Voltage
EN_LDO, EN_PROT, EN_
SW Input Pulldown Current
HOLD Input Threshold
Voltage
HOLD Input Pullup
VIH
IEN_PD
RESET Voltage Threshold
LOW
VOUT_LDO to RESET Delay
CT Ramp Current
CT Ramp Threshold
RESET Output-Voltage Low
RESET Open-Drain
Leakage Current
0.7
EN_ is internally pulled low to SGND
VIH
1
V
µA
1.4
VIL
0.4
V
IHOLD_PU
HOLD is internally pulled high to
OUT_LDO
90.0
92.5
95.0
VRESET_H
RESET goes HIGH when rising VOUT_
LDO crosses this threshold,
FB_LDO = SGND
%VOUT_LDO
RESET goes HIGH when rising VFB_
LDO crosses this threshold
90.0
92.5
95.0
%VFB_LDO
RESET goes LOW when falling VOUT_
LDO crosses this threshold,
FB_LDO = SGND
88
90
92
%VOUT_LDO
RESET goes LOW when falling VFB_
LDO crosses this threshold
88
90
92
%VFB_LDO
RESET
RESET Voltage Threshold
HIGH
2
VIL
VRESET_L
tRESET_FALL
0.6
VOUT_LDO falling, 0.1V/µs
µA
19
µs
ICT
VCT = 0V
1.50
2
2.35
µA
VCT_TH
VCT rising
1.190
1.235
VOL
ILEAK_RESET
1.270
V
ISINK = 1mA, output asserted
0.1
V
Output not asserted
150
nA
1.27
V
LOAD DUMP PROTECTOR (MAX15009 only)
FB_PROT Threshold
Voltage
VTH_PROT
FB_PROT Threshold
Hysteresis
VHYST
FB_PROT Input Current
IFB_PROT
FB_PROT rising
1.235
4
VFB_PROT = 1.4V
Startup Response Time
tSTART
EN_PROT rising, EN_LDO = IN, to
VGATE = 0.5V
GATE Rise Time
tGATE
GATE rising to +8V, VSOURCE = 0V
www.maximintegrated.com
1.20
-100
%VTH_PROT
+100
nA
20
µs
1
ms
Maxim Integrated │ 4
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Electrical Characteristics (continued)
(VIN = +14V, VSGND = VPGND = 0V, CGATE = 6000pF, CIN = 10μF (ESR < 1.5Ω), COUT_LDO = 22μF (ceramic), COUT_SW = 1μF,
VOUT_LDO = 5V, CT = open, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
FB_PROT to GATE TurnOff Propagation Delay
GATE Output High Voltage
GATE Output Pulldown
Current
SYMBOL
tOV
VGATE - VIN
IGATEPD
GATE Charge-Pump
Current
IGATE
GATE-to-SOURCE Clamp
Voltage
VCLMP
CONDITIONS
MIN
TYP
FB_PROT rising from VTH_PROT
-250mV to VTH_PROT + 250mV
MAX
UNITS
0.6
µs
VSOURCE = VIN = 5.5V,
RGATE to IN = 1MΩ
VIN +
3.2
VIN +
3.5
VIN +
3.8
VSOURCE = VIN; VIN ≥ 14V,
RGATE to IN = 1MΩ
VIN +
7.0
VIN +
8.1
VIN +
9.5
VGATE = 5V, VEN_PROT = 0V
63
100
GATE = SGND
45
12
V
mA
µA
16
18
V
36
70
mV
SWITCH
Switch Dropout
Switch Current Limit
Current-Limit Selector ILIM
Voltage
OC_DELAY Timeout
Threshold
OC_DELAY Timeout Pullup
Current
OC_DELAY Timeout
Pulldown Current
Minimum OC_DELAY
Timeout
DVSW
ISW_LIM
VILIM
Note
Note
Note
Note
ILIM = OUT_LDO, VIN = 8V
170
200
240
RLIM = 100kΩ to SGND,
VOUT_LDO = 5V, VIN = 8V
85
100
120
RLIM = 39kΩ to SGND,
VOUT_LDO = 5V, VIN = 8V
30
40
50
RLIM = 100kΩ
VOC_DELAY
IOC_DELAY_UP
VOC_DELAY = 0.5V rising
IOC_DELAY_DOWN VOC_DELAY = 0.5V, falling
tOC_DELAY_MIN
EN_SW to OUT_SW
Turn-On Time
EN_SW to OUT_SW
Turn-Off Propagation Delay
DVSW = VOUT_LDO - VOUT_SW, IOUT_
SW = 100mA, VOUT_LDO = 5V,
no external MOSFET
tOV_SW
0.395
mA
V
1.194
1.235
1.270
V
12.5
16.0
21.3
µA
0.75
1.00
1.40
µA
COC_DELAY is unconnected
12
µs
OUT_SW rising to +0.5V,
ROUT_SW = 1kΩ
38
µs
EN_SW falling, VOUT_LDO - VOUT_SW
rising to +1V, ROUT_SW = 1kΩ, VOUT_
LDO = 5V
18
µs
1: Specifications to -40°C are guaranteed by design and not production tested.
2: 1.8V is the minimum limit for proper HOLD functionality.
3: Dropout is defined as VIN - VOUT_LDO when VOUT_LDO is 98% of the value of VOUT_LDO for VIN = VOUT_LDO + 1.5V.
4: Maximum output current may be limited by the power dissipation of the package.
www.maximintegrated.com
Maxim Integrated │ 5
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Typical Operating Characteristics
(VIN = VEN_LDO = VEN_PROT = VEN_SW = +14V, CIN = 10μF, COUT_LDO = 22μF, COUT_SW = 1μF, VOUT_LDO = +5V, FB_LDO = SGND,
TA = +25°C, unless otherwise specified.)
LDO GROUND CURRENT
vs. LOAD CURRENT
TA = +25°C
64
62
TA = +85°C
60
58
TA = +125°C
56
70
-60
-70
IOUT_LDO = 10mA
400
350
-90 10
100
1k
10k
100k
1M
250
200
FREQUENCY (Hz)
5.02
5.00
4.98
4.96
4.94
4.92
-50
-25
0
25
50
75
100 125 150
4.90
MAX15009 toc07
IOUT_LDO = 300mA
(PULSED)
0
100
200
300
IOUT_LDO (mA)
LDO LOAD-TRANSIENT RESPONSE
MAX15009 toc09
MAX15009 toc08
5
MAX15009 toc03
5.06
LDO LOAD-TRANSIENT RESPONSE
IOUT_LDO = 10mA
4
5.08
TEMPERATURE (°C)
LDO OUTPUT VOLTAGE
vs. INPUT VOLTAGE
6
5.10
5.04
300
100
20 40 60 80 100 120 140
LDO LOAD REGULATION
150
-80
0
TEMPERATURE (°C)
VOUT_LDO (V)
-50
0 -60 -40 -20
MAX15009 toc05
MAX15009 toc04
-40
15
5
TA = +125°C
VIN UVLO HYSTERESIS
vs. TEMPERATURE
-30
20
10
TA = +85°C
LDO POWER-SUPPLY
REJECTION RATIO vs. FREQUENCY
-20
LDO PSRR (dB)
80
LOAD CURRENT (mA)
-10
VOUT_LDO (V)
25
TA = -40°C
LOAD CURRENT (mA)
0
30
50 0 25 50 75 100 125 150 175 200 225 250 275 300
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
UVLO HYSTERESIS (mV)
0
TA = +25°C
60
54
52
90
MAX15009 toc02
100
35
ISHDN (A)
68
66
110
GROUND CURRENT (A)
TA = -40°C
70
GROUND CURRENT (A)
MAX15009 toc01
74
72
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX15009 toc06
LDO GROUND CURRENT
vs. LOAD CURRENT
IOUT_LDO
100mA/div
IOUT_LDO
100mA/div
0A
3
0A
2
1
0
VOUT_LDO
5V, AC-COUPLED
100mV/div
VOUT_LDO
5V, AC-COUPLED
20mV/div
0
5
10
15
20
VIN (V)
www.maximintegrated.com
25
30
35
40
2ms/div
400s/div
Maxim Integrated │ 6
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Typical Operating Characteristics (continued)
(VIN = VEN_LDO = VEN_PROT = VEN_SW = +14V, CIN = 10μF, COUT_LDO = 22μF, COUT_SW = 1μF, VOUT_LDO = +5V, FB_LDO = SGND,
TA = +25°C, unless otherwise specified.)
LDO OUTPUT VOLTAGE
vs. TEMPERATURE
SWITCH LOAD-TRANSIENT RESPONSE
IOUT_SW
100mA/div
VOUT_SW
5V, AC-COUPLED
100mV/div
IOUT_LDO = 100mA
4.90
IOUT_LDO = 100mA
IOUT_SW = 100mA
VIN = 8V
-50
-25
0
25
50
75
100 125 150
LINE-TRANSIENT RESPONSE
LDO DROPOUT VOLTAGE
vs. LOAD CURRENT
SWITCH DROPOUT VOLTAGE
vs. LOAD CURRENT
VOUT_LDO
3.3V, AC-COUPLED
20mV/div
VOUT_SW
3.3V, AC-COUPLED
20mV/div
VOUT_PROT
10V/div
900
800
700
600
500
400
300
200
100
0V
0
40ms/div
0
100
200
20
15
10
5
0
300
IOUT_LDO = 10mA
0
50
IOUT_SW (mA)
IOUT_LDO = 100mA
IOUT_SW = 70mA
EN_LDO = EN_SW = IN
VOUT_LDO
5V/div
IOUT_SW = 10mA
10
5
30
55
80
TEMPERATURE (°C)
105
130
0V
0V
0V
VOUT_SW
5V/div
www.maximintegrated.com
20
VIN
20V/div
VRESET
5V/div
IOUT_SW = 100mA
30
-20
25
MAX15009 toc17
40
-45
30
STARTUP RESPONSE THROUGH VIN
MAX15009 toc16
SWITCH DROPOUT VOLTAGE (mV)
IOUT_LDO = 10mA
50
0
35
IOUT_LDO (mA)
SWITCH DROPOUT VOLTAGE
vs. TEMPERATURE
60
40
MAX15009 toc14
LDO DROPOUT VOLTAGE (mV)
0V
0V
40ms/div
1000
VIN
10V/div
VOUT_PROT
20V/div
400s/div
TEMPERATURE (°C)
MAX15009 toc13
0V
VOUT_LDO
3.3V, AC-COUPLED
50mV/div
VOUT_SW
3.3V, AC-COUPLED
50mV/div
VOUT_LDO
5V, AC-COUPLED
100mV/div
IOUT_LDO = 300mA
4.85
4.80
0A
MAX15009 toc15
5.00
4.95
MAX15009 toc12
VIN
20V/div
SWITCH DROPOUT VOLTAGE (mV)
VOUT_LDO (V)
IOUT_LDO = 10mA
MAX15009 toc10
IOUT_LDO = 100A
5.05
LINE-TRANSIENT RESPONSE
MAX15009 toc11
5.10
0V
20ms/div
Maxim Integrated │ 7
100
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Typical Operating Characteristics (continued)
(VIN = VEN_LDO = VEN_PROT = VEN_SW = +14V, CIN = 10μF, COUT_LDO = 22μF, COUT_SW = 1μF, VOUT_LDO = +5V, FB_LDO = SGND,
TA = +25°C, unless otherwise specified.)
STARTUP RESPONSE THROUGH EN
SHUTDOWN RESPONSE THROUGH EN
MAX15008 toc19
0V
VIN
20V/div
VEN_LDO
5V/div
0V
VRESET
5V/div
14V
VEN_LDO
5V/div
VIN
10V/div
0V
IOUT_LDO = 100mA
IOUT_SW = 70mA
VEN_LDO = VEN_SW
VRESET
5V/div
0V
VOUT_LDO
5V/div
0V
VOUT_SW
5V/div
IOUT_LDO = 100mA
IOUT_SW = 70mA
EN_LDO = VEN_SW = IN
VOUT_LDO
5V/div
0V
VOUT_SW
5V/div
0V
0V
20ms/div
MAX15009 toc21
VOUT_LDO
5V/div
GROUND CURRENT DISTRIBUTION
HISTOGRAM (TA = -40°C)
70
60
0V
HOLD PULLED UP
TO OUT_LDO
HOLD
5V/div
0V
50
40
30
20
0V
GROUND CURRENT DISTRIBUTION
HISTOGRAM (TA = +125C)
80
70
60
50
40
30
10
0
200ms/div
67
69
71
73
75
77
79
81
0
51 53 55 57 59 61 63 65 67 69 71
GROUND CURRENT (A)
GROUND CURRENT (A)
PROTECTOR GATE VOLTAGE
vs. INPUT VOLTAGE (MAX15009 ONLY)
PROTECTOR STARTUP RESPONSE
MAX15009 toc25
MAX15009 toc24
50
45
40
VIN
10V/div
0V
VGATE
30
VGATE
10V/div
25
20
0V
15
VOUT_PROT
10V/div
10
VIN
5
0
0
5
10
15
20
IOUT_PROT = 1A
25
30
35
40
0V
10ms/div
VIN (V)
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0V
0V
20
10
RESET
5V/div
90
NUMBER OF PARTS
NUMBER OF PARTS
0V
35
0V
0V
VOUT_SW
5V/div
MAX15009 toc22
VEN_LDO
5V/div
GATE VOLTAGE (V)
IOUT_LDO = 100mA
IOUT_SW = 70mA
EN_LDO = EN_SW
6V
2ms/div
LDO, EN_LDO, AND HOLD TIMING
VOUT_LDO
5V/div
MAX15008 toc20
MAX15009 toc23
VRESET
5V/div
SHUTDOWN RESPONSE THROUGH VIN
MAX15008 toc18
VIN
Maxim Integrated │ 8
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Typical Operating Characteristics (continued)
(VIN = VEN_LDO = VEN_PROT = VEN_SW = +14V, CIN = 10μF, COUT_LDO = 22μF, COUT_SW = 1μF, VOUT_LDO = +5V, FB_LDO = SGND,
TA = +25°C, unless otherwise specified.)
MAX15009 toc27
VIN
20V/div
0V
IOUT_PROT = 1A
VOV = 25V
VGATE
20V/div
VGATE
20V/div
0V
VOUT_PROT
20V/div
0V
VOUT_PROT
20V/div
IOUT_PROT = 1A
OV THRESHOLD = 35V
CRESET = 2.2nF
1.2
1.0
0.8
0.6
CRESET = 220pF
0.2
-50
-25
0
0
25
0
50
75
2
4
6
200
TA = +125°C
180
160
120
TA = -40°C
100
TA = +85°C
80
60
TA = +25°C
20
40
60
80 100 120 140 160 180 200
INTERNAL PRESET SWITCH CURRENT LIMIT
vs. TEMPERATURE
IOC_DELAY_UP AND IOC_DELAY_DOWN
vs. TEMPERATURE
MAX15009 toc31
220
210
200
190
180
170
160
150
-50
-25
0
25
50
75
100 125 150
TEMPERATURE (°C)
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18
16
MAX15009 toc32
ILIM RESISTANCE (k)
OC_DELAY PULLUP/PULLDOWN CURRENT (A)
TEMPERATURE (°C)
230
10
140
20
100 125 150
240
8
SWITCH CURRENT LIMIT
vs. ILIM RESISTANCE
40
250
PRESET CURRENT LIMIT (mA)
2
CRESET (nF)
SWITCH CURRENT LIMIT (mA)
MAX15009 toc29
RESET TIMEOUT DELAY (ms)
1.6
0.4
3
40ms/div
1.8
1.4
4
1
RESET TIMEOUT DELAY
vs. TEMPERATURE
2.0
5
0V
400s/div
0
0V
6
MAX15009 toc30
0V
7
RESET TIMEOUT DELAY (ms)
MAX15009 toc26
VIN
10V/div
RESET TIMEOUT DELAY
vs. CRESET
OVERVOLTAGE LIMIT FAULT
MAX15009 toc28
OVERVOLTAGE SWITCH FAULT
IOC_DELAY_DOWN
14
12
10
8
6
4
IOC_DELAY_UP
2
0
-50
-25
0
25
50
75
100 125 150
TEMPERATURE (°C)
Maxim Integrated │ 9
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Pin Description
PIN
1–4, 8, 11, 14,
26, 29–32
NAME
MAX15009
MAX15011
N.C.
—
FUNCTION
No Connection. Not internally connected.
1–4, 8,
10–14, 18,
26, 29–32
—
N.C.
5
SGND
SGND
Signal Ground
6
PGND
PGND
Ground. PGND is also the return path for the overvoltage protector pulldown current
for the MAX15009. In this case, connect PGND to SGND at the negative terminal of
the bypass capacitor connected to the source of the external MOSFET. For the
MAX15011, connect PGND to SGND together to the local ground plane.
7
RESET
RESET
Active-Low Open-Drain Reset Output. RESET is low while OUT_LDO is below the
reset threshold. Once OUT_LDO has exceeded the reset threshold, RESET remains
low for the duration of the reset timeout period then goes high.
9
CT
CT
Reset Timeout Adjust Input. Connect a capacitor (CRESET) from CT to ground to
adjust the reset timeout period. See the Setting the RESET Timeout Period section.
—
Overvoltage-Threshold Adjustment Input. Connect FB_PROT to an external resistive
voltage-divider network to adjust the desired overvoltage threshold. Use FB_PROT to
monitor a system input or output voltage. See the Setting the Overvoltage Threshold
(MAX15009 Only) section.
10
FB_PROT
12
GATE
—
Protector Gate Drive Output. Connect GATE to the gate of an external n-channel
MOSFET. GATE is the output of a charge pump with a 45µA pullup current to 8.1V
(typ) above IN during normal operation. GATE is quickly turned off through a 63mA
internal pulldown during an overvoltage condition. GATE then remains low until
FB_PROT has decreased below 96% of the overvoltage threshold. GATE pulls
low when EN_PROT is low.
13
SOURCE
—
Output-Voltage Sense Input. Connect SOURCE to the source of the external
n-channel MOSFET.
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Maxim Integrated │ 10
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Pin Description (continued)
PIN
NAME
FUNCTION
MAX15009
MAX15011
15
FB_LDO
FB_LDO
16
EN_LDO
EN_LDO
17
EN_SW
EN_SW
18
EN_PROT
—
Protector Enable Input. Drive EN_PROT low to force GATE low and turn off the
external n-channel MOSFET. EN_PROT is internally pulled to SGND by a 1µA
sink current. Connect EN_PROT to IN for normal operation.
19, 20
IN
IN
Regulator Input. Bypass IN to SGND with a 10µF capacitor with an ESR < 1.5Ω.
21, 22
OUT_LDO
OUT_LDO
OC_DELAY
Switch Overcurrent Blanking Time Programming Input. Leave OC_DELAY unconnected
to select the minimum delay timeout before turning the switch off. OC_DELAY is
OC_DELAY
internally pulled to SGND through a 1µA current source. See the Programming the
Switch Overcurrent Blanking Time section.
23
24
ILIM
LDO Regulator Output. Bypass OUT_LDO to SGND with a ceramic capacitor with a
minimum value of 22µF. OUT_LDO has a fixed 5V output or can be adjusted from
1.8V to 11V. See the Setting the Output Voltage section.
ILIM
Switch Current-Limit Set Input. Connect a 10kΩ to 200kΩ resistor from ILIM to
SGND to select the current limit for the internal switch. Connect ILIM to OUT_LDO
to select the internal 170mA (min) current-limit threshold. Do not leave ILIM
unconnected. See the Setting the Switch Current Limit section.
Active-Low Hold Input. If EN_LDO is high when HOLD is forced low, the regulator
latches the state of the EN_LDO input and allows the regulator to remain turned
on when EN_LDO is subsequently pulled low. To shut down the regulator, release
HOLD after EN_LDO is pulled low. If HOLD functionality is unused, connect HOLD
to OUT_LDO or leave unconnected. HOLD is internally pulled up to OUT_LDO
through a 0.6µA current source. See the Control Logic section.
25
HOLD
HOLD
27, 28
OUT_SW
OUT_SW
—
EP
EP
www.maximintegrated.com
LDO Voltage Feedback Input. Connect FB_LDO to SGND to select the preset +5V
output voltage. Connect FB_LDO to an external resistive voltage-divider for adjustable
output operation. See the Setting the Output Voltage section.
Active-High LDO Enable Input. Connect EN_LDO to IN or to a logic-high voltage
to
turn on the regulator. To place the LDO in shutdown, pull EN_LDO low or leave
unconnected and leave HOLD unconnected. EN_LDO is internally pulled to SGND
through a 1FA current sink. See the Control Logic section.
Active-High Switch Enable Input. Connect EN_SW to IN or to a logic-high voltage
to turn on the switch. Pull EN_SW low or leave unconnected to place the switch in
shutdown. EN_SW is internally pulled to SGND through a 1µA current sink.
Switch Output. Bypass OUT_SW to SGND with a minimum 0.1µF ceramic capacitor.
Exposed Pad. Connect EP to SGND plane. EP also functions as a heatsink to
maximize thermal dissipation. Do not use as the main ground connection.
Maxim Integrated │ 11
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Functional Diagram
IN
VIN
ENABLE LDO
HOLD
LDO
IN
EN_LDO
HOLD
VREF 1.235V
BIAS AND VOLTAGE
REFERENCE
CONTROL
LOGIC
5V LDO
OUTPUT
OUT_LDO
M
U
X
FB_LDO
0.124V
2µA
CT
0.925 x VREF
RESET
VREF
RESET
OUTPUT
OUT_LDO
ILIM
SWITCH
16µA
OUT_SW
VGATE
SWITCH
OUTPUT
OUT_SW
VREF
S
ENABLE SWITCH
EN_SW
Q
0.1V
R
OC_DELAY
1µA
IN
GATE UVLO
4.75V
VIN
GATE
VREF
ENABLE
PROTECTOR
EN_PROT
SOURCE
OVERVOLTAGE PROTECTOR
(MAX15009 ONLY)
EP
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SGND
PROTECTOR
OUTPUT
FB_PROT
PGND
Maxim Integrated │ 12
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Detailed Description
The MAX15009/MAX15011 integrate a 300mA LDO voltage regulator, a current-limited switched output, and an
OVP controller (MAX15009 only). These devices operate
over a wide supply voltage range from 5V to 40V and are
able to withstand load-dump transients up to 45V.
The MAX15009/MAX15011 feature a 300mA LDO regulator that consumes 70μA of current under light-load
conditions and feature a fixed 5V or an adjustable output
voltage (1.8V to 11V). Connect FB_LDO to ground to
select a fixed 5V output voltage, or select the LDO output
voltage by connecting an external resistive voltage-divider
at FB_LDO. The regulator sources at least 300mA of
current and includes a current limit of 330mA (min).
Enable the LDO by pulling EN_LDO high.
The switch features accurate current-limit-sensing
circuitry and is capable of controlling remote loads. Once
enabled, an internal charge pump generates the overdrive
voltage for an internal MOSFET. The switch then starts to
conduct and OUT_SW is charged up to VOUT_LDO. The
switch is enabled when the output voltage of the LDO is
above the RESET threshold voltage (92.5% of the LDO
nominal output value).
An overcurrent condition exists when the current at
OUT_SW (IOUT_SW) exceeds the 200mA (typ) internal
factory-set current-limit threshold or the externally adjustable current-limit threshold. During a continuous overcurrent event, the capacitor connected at OC_DELAY
(COC_DELAY) is charged up to a voltage of 1.235V
with a current (IOC_DELAY_UP). When this voltage is
reached, an overcurrent latch is set and the gate of the
internal MOSFET is discharged, reducing IOUT_SW.
COC_DELAY is then discharged through a pulldown
current, IOC_DELAY_DOWN (IOC_DELAY_UP/16) and the
internal MOSFET remains off until COC_DELAY has been
discharged to 0.1V. After this user-programmable turnoff
delay, the switch turns back on. This charge/discharge
is repeated if the overcurrent condition persists. The
switch returns to normal operation once the overcurrent
condition has been removed.
The OVP controller (MAX15009 only) relies on an external
MOSFET with adequate voltage rating (VDSS) to protect
downstream circuitry from overvoltage transients. The
OVP controller drives the gate of the external n-channel
MOSFET, and is configurable to operate as an overvoltage protection switch or as a closed-loop voltage limiter.
GATE Voltage (MAX15009 Only)
The MAX15009 uses a high-efficiency charge pump
to generate the GATE voltage for the external n-channel MOSFET. Once the input voltage (VIN) exceeds
the undervoltage-lockout (UVLO) threshold, the internal
charge pump fully enhances the external n-channel
MOSFET. An overvoltage condition occurs when the
voltage at FB_PROT goes above the threshold voltage
(VTH_PROT). After VTH_PROT is exceeded, GATE is
quickly pulled to PGND with a 63mA pulldown current.
The MAX15009 includes an internal clamp from GATE
to SOURCE that ensures that the voltage at GATE never
exceeds one diode drop below SOURCE during gate
discharge. The voltage clamp also prevents the GATE-toSOURCE voltage from exceeding the absolute maximum
rating for the VGS of the external MOSFET in case the
source terminal is accidentally shorted to 0V.
Overvoltage Monitoring (MAX15009 Only)
The OVP controller monitors the voltage at FB_PROT
and controls an external n-channel MOSFET, isolating, or
limiting the load during an overvoltage condition. Operation
in OVP switch mode or limiter mode depends on the
connection between FB_PROT and the external MOSFET.
Overvoltage Switch Mode
When operating in OVP switch mode, the FB_PROT
divider is connected to the drain of the external MOSFET.
The feedback path consists of the voltage-divider
tapped at FB_PROT, FB_PROT’s internal comparator,
the internal gate-charge pump/gate pulldown, and the
external n-channel MOSFET (Figure 1). When the programmed overvoltage threshold is exceeded, the internal
comparator quickly pulls GATE to ground and turns off the
VIN
IN
GATE
MAX15009
FB_PROT
SOURCE
PROTECTOR
OUTPUT
SGND
Figure 1. Overvoltage-Limiter Switch Configuration (MAX15009)
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Maxim Integrated │ 13
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
external MOSFET, disconnecting the power source from
the load. In this configuration, the voltage at the source
of the MOSFET is not monitored. When the voltage at
FB_PROT decreases below the overvoltage threshold,
the MAX15009 raises the voltage at GATE, reconnecting
the load to the power source.
VIN
IN
GATE
MAX15009
PROTECTOR
OUTPUT
Overvoltage-Limiter Mode (MAX15009 Only)
When operating in overvoltage-limiter mode, the feedback path consists of SOURCE, FB_PROT’s internal
comparator, the internal gate-charge pump/gate pulldown,
and the external n-channel MOSFET (Figure 2). This
configuration results in the external MOSFET operating as a
hysteretic voltage regulator.
During normal operation, GATE is enhanced 8.1V above
VIN. The external MOSFET source voltage is monitored
through a resistive voltage-divider between SOURCE
and FB_PROT. When VSOURCE exceeds the adjustable
overvoltage threshold, an internal pulldown switch discharges the gate voltage and quickly turns the MOSFET
off. Consequently, the source voltage begins to fall. The
VSOURCE fall time is dependent on the MOSFET’s gate
charge, the internal charge-pump current, the output load,
and any load capacitance at SOURCE. When the voltage
at FB_PROT is below the overvoltage threshold by an
amount equal to the hysteresis, the charge pump restarts
and turns the MOSFET back on. In this way, the OVP
controller attempts to regulate VSOURCE around the
overvoltage threshold. SOURCE remains high during
overvoltage transients and the MOSFET continues to
conduct during an overvoltage event. The hysteresis of
the FB_PROT comparator and the gate turn-on delay
force the external MOSFET to operate in a switched on/
off sequence during an overvoltage event.
Exercise caution when operating the MAX15009 in
voltage-limiting mode for long durations. Care must be
taken against prolonged or repeated exposure to overvoltage events while delivering large amounts of load
current, as the power dissipation in the external MOSFET
may be high under these conditions. To prevent damage to the MOSFET, implement proper heatsinking. The
capacitor tied between SOURCE and ground may also
be damaged if the ripple current rating for the capacitor
is exceeded.
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SOURCE
FB_PROT
SGND
Figure 2. Overvoltage Limiter (MAX15009)
As the transient voltage decreases, the voltage at
SOURCE falls. For fast-rising transients and very large
MOSFETs, connect an additional capacitor from GATE to
PGND. This capacitor acts as a voltage-divider working
against the MOSFET’s drain-to-gate capacitance. If using
a very low gate-charge MOSFET, additional capacitance
from GATE to ground might be required to reduce the
switching frequency.
Control Logic
The MAX15009/MAX15011 LDO features two logic inputs,
EN_LDO and HOLD. For example, when the ignition key
signal drives EN_LDO high, the regulator turns on and
remains on even if EN_LDO goes low, as long as HOLD
is forced low and stays low after initial regulator powerup. In this state, releasing HOLD turns the regulator
output (OUT_LDO) off. This feature makes it possible to
implement a self-holding circuit without external components. Forcing EN_LDO low and HOLD high (or
unconnected) places the regulator into shutdown mode,
reducing the supply current to less than 16μA. Table 1
shows the state of OUT_LDO with respect to EN_LDO
and HOLD. Leave HOLD unconnected or connect directly
to OUT_LDO to allow the EN_LDO input to act as a
standard on/off logic input for the regulator.
Maxim Integrated │ 14
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Table 1. EN_LDO/HOLD Truth/State Table
EN_LDO
HOLD
OUT_LDO
Initial State
Low
Don’t care
OFF
EN_LDO is pulled to SGND through an internal pulldown. HOLD
is unconnected and is internally pulled up to OUT_LDO. The
regulator is disabled.
Turn-On State
High
Don’t care
ON
EN_LDO is externally driven high turning regulator on. HOLD is
pulled up to OUT_LDO.
Hold Setup State
High
Low
ON
HOLD is externally pulled low while EN_LDO remains high
(latches EN_LDO state).
Hold State
Low
Low
ON
EN_LDO is driven low or left unconnected. HOLD remains
externally pulled low keeping the regulator on.
Off State
Low
High or
unconnected
OFF
HOLD is driven high or left unconnected while EN_LDO is low.
The regulator is turned off and EN_LDO/HOLD logic returns to the
initial state.
OPERATION STATE
COMMENT
Applications Information
Setting the Output Voltage
The MAX15009/MAX15011 feature dual-mode operation:
these devices operate in either a preset voltage mode
or an adjustable mode. In preset-voltage mode, internal
feedback resistors set the linear regulator output voltage
(VOUT_LDO) to 5V. To select the preset 5V output voltage,
connect FB_LDO to SGND.
VIN
IN
OUT_LDO
MAX15009
MAX15011
FB_LDO
R2
To select an adjustable output voltage between 1.8V and
11V, use two external resistors connected as a voltagedivider to FB_LDO (Figure 3). Set the output voltage
using the following equation:
VOUT_LDO = VFB_LDO x (R1 + R2) / R2
where VFB_LDO = 1.235V and R2 ≤ 50kΩ.
Setting the RESET Timeout Period
The reset-timeout period is adjustable to accommodate
a variety of applications. Set the reset-timeout period
by connecting a capacitor (CRESET) between CT and
SGND. Use the following formula to select the resettimeout period (tRESET):
tRESET = CRESET x VCT_TH/ICT
where tRESET is in seconds and CRESET is in μF.
VCT_TH is the CT ramp threshold in volts and ICT is the
CT ramp current in μA, as described in the Electrical
Characteristics table.
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R1
SGND
Figure 3. Setting the LDO Output Voltage
Leave CT open to select a typical reset timeout of 19μs.
To maintain reset accuracy, use a low-leakage type of
capacitor.
Setting the Switch Current Limit
The switch block features accurate current-limit-sensing
circuitry. A resistor connected from ILIM to SGND can be
used to select the current-limit threshold using the following relationship:
ISW_LIM (mA) = RILIM (kΩ) x 1mA/kΩ
where 20kΩ ≤ RILIM ≤ 200kΩ.
Connect ILIM to OUT_LDO to select the default current
limit of 200mA (typ).
Maxim Integrated │ 15
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Programming the Switch Overcurrent
Blanking Time
The switch provides an adjustable overcurrent blanking
time to allow the safe charge of large capacitive loads.
When an overcurrent event is detected, a delay period
elapses before the condition is latched and the internal
MOSFET is turned off. This period is the overcurrent
delay (tOC_DELAY). Set the overcurrent delay using the
following equation:
tOC_DELAY = COC_DELAY x VOC_DELAY/IOC_DELAY_UP
where tOC_DELAY is in seconds and COC_DELAY is in μF.
VOC_DELAY is the overcurrent-delay timeout threshold
voltage in volts and IOC_DELAY_UP is the overcurrentdelay timeout pullup current in μA, as seen in the
Electrical Characteristics table.
Ensure that the switch is not disabled due to a large startup
inrush current by selecting a large enough value for overcurrent blanking time. Assume that the current available for
charging the total switch output capacitance (COUT_SW)
is the difference between the current-limit threshold value
(ISW_LIM), and the nominal DC load current at OUT_SW
(IOUT_SW_NOM), and select the COC_DELAY using the
following relationship:
C OC_DELAY ≥
I OC_DELAY_UP × VOUT_LDO × C OUT_SW
VOC_DELAY × (I SW_LIM − I OUT_SW_NOM )
COC_DELAY also affects the length of time before the
MAX15009/MAX15011 attempt to turn the switch back
on. Set the autoretry delay using the following equation:
tOC_RETRY = COC_DELAY x
VOC_DELAY/IOC_DELAY_DOWN
IN
VIN
R5
FB_PROT
SOURCE
COC_DELAY should be a low-leakage type of capacitor
with a minimum value of 100pF.
Setting the Overvoltage Threshold
(MAX15009 Only)
The MAX15009 provides an accurate means to set
the overvoltage threshold for the OVP controller using
FB_PROT. Use a resistive voltage-divider to set the
desired overvoltage threshold (Figure 4). FB_PROT has a
rising 1.235V threshold with a 4% falling hysteresis.
Begin by selecting the total end-to-end resistance, RTOTAL
= R3 + R4. Choose RTOTAL to yield a total current equivalent to a minimum of 100 x IFB_PROT (FB_PROT’s
input maximum bias current) at the desired overvoltage
threshold. See the Electrical Characteristics table.
For example:
With an overvoltage threshold (VOV) set to 20V, RTOTAL
< 20V/(100 x IFB_PROT), where IFB_PROT is FB_PROT’s
maximum 100nA bias current:
RTOTAL < 2MΩ
Use the following formula to calculate R4:
R4 = VTH_PROT x RTOTAL / VOV
where VTH_PROT is the 1.235V FB_PROT rising
threshold and VOV is the desired overvoltage threshold.
R4 = 124kΩ:
RTOTAL = R3 + R4
where R3 = 1.88MΩ. Use a standard 1.87MΩ resistor.
A lower value for total resistance dissipates more power,
but provides better accuracy and robustness against
external disturbances.
VIN
GATE
MAX15009
where tOC_RETRY is in seconds, COC_DELAY is in μF,
VOC_DELAY is in volts, and IOC_DELAY_DOWN is in μA.
PROTECTOR
OUTPUT
IN
GATE
MAX15009
SOURCE
PROTECTOR
OUTPUT
R3
R6
FB_PROT
SGND
SGND
R4
Figure 4. Setting the Overvoltage Threshold (MAX15009)
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Maxim Integrated │ 16
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Input Transients Clamping
When the external MOSFET is turned off during an
overvoltage event, stray inductance in the power
path may cause additional input-voltage spikes that
exceed the VDSS rating of the external MOSFET, or the
absolute maximum rating for the MAX15009. Minimize stray
inductance in the power path using wide traces and
minimize the loop area included by the power traces and
the return ground path.
For further protection, add a zener diode or transient voltage suppressor (TVS) rated below the absolute maximum
rating limits (Figure 5).
External MOSFET Selection
Select the external MOSFET with adequate voltage
rating (VDSS) to withstand the maximum expected loaddump input voltage. The on-resistance of the MOSFET
(RDS(ON)) should be low enough to maintain a minimal
voltage drop at full load, limiting the power dissipation of
the MOSFET.
During regular operation, the power dissipated by the
MOSFET is:
PNORMAL = ILOAD2 x RDS(ON)
Normally, this power loss is small and is safely handled
by the MOSFET; however, when operating the MAX15009
in overvoltage-limiter mode under prolonged or frequent
overvoltage events, select an external MOSFET with an
appropriate power rating.
During an overvoltage event, the power dissipation in
the external MOSFET is proportional to both load current
and to the drain-source voltage, resulting in high power
dissipated in the MOSFET (Figure 6). The power
dissipated across the MOSFET is:
POV_LIMITER = VQ1 x ILOAD
where VQ1 is the voltage across the MOSFET’s drain and
source during overvoltage-limiter operation, and ILOAD is
the load current.
Overvoltage-Limiter Mode Switching
Frequency
When the MAX15009 is configured in overvoltage-limiter
mode, the external n-channel MOSFET is subsequently
switched on and off during an overvoltage event. The
output voltage at OUT_PROT resembles a periodic
sawtooth waveform. Calculate the period of the waveform
(tOVP) by summing three time intervals (Figure 7):
tOVP = t1 + t2 + t3
where t1 is the VSOURCE output discharge time, t2 is the
GATE delay time, and t3 is the VSOURCE output charge
time.
During an overvoltage event, the power dissipated inside
the MAX15009 is due to the gate pulldown current
VMAX
VIN
VSOURCE
ILOAD
IN
IN
MAX15009
TVS
VOV
+ VQ1 -
VSOURCE
GATE
MAX15009
GATE
LOAD
TVS
SOURCE
LOAD
SOURCE
FB_PROT
SGND
Figure 5. Protecting the MAX15009 Input from High-Voltage
Transients
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SGND
Figure 6. Power Dissipated Across MOSFETs During an
Overvoltage Fault (Overvoltage Limiter Mode)
Maxim Integrated │ 17
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
GATE Delay Time (t2)
GATE
SOURCE
When SOURCE falls 4% below the overvoltage-threshold
voltage, the internal current sink is disabled and the
internal charge pump begins recharging the external
GATE voltage. Due to the external load, the SOURCE
voltage continues to drop until the gate of the MOSFET
is recharged. The time needed to recharge GATE and
reenhance the external MOSFET is approximately:
t2
=
t 2 C iss ×
t3
t1
tOVP
Figure 7. MAX15009 Timing Diagram
(IGATEPD) . This amount of power dissipation is worse
when ISOURCE = 0 (CSOURCE is discharged only by the
internal current sink).
The worst-case internal power dissipation contribution in
overvoltage limiter mode (POVP) in watts can be approximated using the following equation:
POVP = VOV × 0.98 × I GATEPD ×
t1
t OVP
where VOV is the overvoltage threshold voltage in volts
and IGATEPD is 100mA (max) GATE pulldown current.
Output Discharge Time (t1)
When the voltage at SOURCE exceeds the adjusted overvoltage threshold, GATE’s internal pulldown is enabled
until VSOURCE drops by 4%. The internal current sink
(IGATEPD) and the external load current (ILOAD) discharge
the external capacitance from SOURCE to ground.
Calculate the discharge time (t1) using the following
equation:
=
t 1 C SOURCE ×
0.04 × VOV
ILOAD + I GATEPD
where t1 is in ms, VOV is the adjusted overvoltage threshold in volts, ILOAD is the external load current in mA, and
IGATEPD is the 100mA (max) internal pulldown current of
GATE. CSOURCE is the value of the capacitor connected
between the source of the MOSFET and PGND in μF.
www.maximintegrated.com
VGS(TH) + VF
I GATE
where t2 is in μs, Ciss is the input capacitance of the
MOSFET in pF, and VGS(TH) is the GATE-to-SOURCE
threshold voltage of the MOSFET in volts. VF is the 0.7V
(typ) internal clamp-diode forward voltage of the MOSFET
in volts, and IGATE is the charge-pump current 45μA (typ).
Any external capacitance between GATE and PGND
adds up to Ciss.
During t2, the SOURCE capacitance (CSOURCE) loses
charge through the output load. The voltage across
CSOURCE, ΔV2, decreases until the MOSFET reaches its
VGS(TH) threshold. Approximate ΔV2 using the following
formula:
ILOAD × t 2
∆V2 =
C SOURCE
SOURCE Output Charge Time (t3)
Once the GATE voltage exceeds the GATE-to-SOURCE
threshold (VGS(TH)) of the external MOSFET, the
MOSFET turns on and the charge through the internal
charge pump with respect to the drain potential (QG)
determines the slope of the output voltage rise. The time
required for the SOURCE voltage to rise again to the
overvoltage threshold is:
t3 =
C rss × ∆VSOURCE
I GATE
where VSOURCE = (VOV x 0.04) + V2 in volts, and Crss
is the MOSFET’s reverse transfer capacitance in pF. Any
external capacitance between GATE and PGND adds up
to Crss.
Maxim Integrated │ 18
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Power Dissipation/Junction Temperature
Under these circumstances the corresponding internal
power dissipation contribution (POVP) calculated in the
previous section should also be included in the total
power dissipation (PDISS).
The internal power dissipation due to the LDO can be
calculated as:
For a given ambient temperature (TA) calculate the
junction temperature (TJ) as follows:
During normal operation, the MAX15009/MAX15011
have two main sources of internal power dissipation: the
LDO and the switched output.
PLDO =
(VIN − VOUT_LDO ) × (I OUT_LDO + I OUT_SW )
where VIN is the LDO input supply voltage in volts,
VOUT_LDO is the output voltage of the LDO in volts,
IOUT_LDO is the LDO total load current in mA, and
IOUT_SW is the switch load current in mA.
Calculate the power dissipation due to the switch as:
PSW = ΔVSW ×IOUT_SW
where ΔVSW is the switch dropout voltage in volts for the
given IOUT_SW current in mA.
The total power dissipation (PDISS) in mW as:
PDISS = PLDO + PSW
For prolonged exposure to overvoltage events, use the
VIN voltage expected during overvoltage conditions.
www.maximintegrated.com
TJ = TA + PDISS x θJA
where TJ and TA are in °C and θJA is the junction-toambient thermal resistance in °C/W, as listed in the
Absolute Maximum Ratings section.
The junction temperature should never exceed +150°C
during normal operation.
Thermal Protection
When the junction temperature exceeds TJ = +160°C, the
MAX15009/MAX15011 shut down to allow the device to
cool. When the junction temperature drops to +140°C, the
thermal sensor turns all enabled blocks on again, resulting in a cycled output during continuous thermal-overload
conditions. Thermal protection protects the MAX15009/
MAX15011 from excessive power dissipation. For
continuous operation, do not exceed the absolute
maximum junction temperature rating of +150°C.
Maxim Integrated │ 19
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Typical Operating Circuits
VOUT1
DC-DC
MAX5073
VOUT2
CSOURCE
5V TO 40V INPUT
GATE SOURCE
PGND
IN
SGND
CIN
LDO ON/OFF
SWITCH ON/OFF
PROTECTOR ON/OFF
HOLD
FB_PROT
MAX15009
COUT_SW
EN_LDO
OUT_LDO
EN_PROT
FB_LDO
HOLD
CT
RILIM
OC_DELAY
CRESET
HOLD
www.maximintegrated.com
RESET/EN
I/O
IN
OUT_SW
COUT_SW
5V
300mA
VCC
COUT_LDO
EN_SW
FB_LDO
HOLD
CT
SWITCH OUTPUT
OUT_LDO
EN_LDO
RESET
ILIM
RILIM
µC
RPU
RESET
MAX15011
SWITCH ON/OFF
VCC
COUT_LDO
COC_DELAY
CIN
LDO ON/OFF
5V
300mA
EN_SW
ILIM
5V TO 40V INPUT
SWITCH OUTPUT
OUT_SW
OC_DELAY
CRESET
RPU
µC
RESET/EN
I/O
PGNDSGND
COC_DELAY
Maxim Integrated │ 20
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Pin Configurations (continued)
Selector Guide
ILIM
OC_DELAY
OUT_LDO
OUT_LDO
IN
IN
N.C.
EN_SW
PART
MAX15009
24
23
22
21
20
19
18
17
MAX15011
TOP VIEW
HOLD 25
16
EN_LDO
N.C. 26
15
FB_LDO
OUT_SW 27
14
N.C.
13
N.C.
12
N.C.
OUT_SW 28
MAX15011
N.C. 29
N.C. 30
N.C. 31
*EP
+
1
2
3
4
5
6
7
8
N.C.
N.C.
N.C.
N.C.
SGND
PGND
RESET
N.C.
N.C. 32
*EP = EXPOSED PAD
www.maximintegrated.com
TQFN
(5mm x 5mm)
11
N.C.
10
N.C.
9
CT
LDO
SWITCHED
OUTPUT
OVP
CONTROLLER
√
√
√
√
√
—
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
32 TQFN
T3255+4
21-0140
90-0012
Maxim Integrated │ 21
MAX15009/MAX15011
300mA LDO Regulators with
Switched Output and Overvoltage Protector
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
8/07
Initial release
1
1/08
Removed future product asterisks, updated Electrical Characteristics table and
Typical Operating Characteristics section.
1, 2, 6, 8
2
11/14
No /V OPN in Ordering Information; removed automotive references and deleted
Load-Dump section
1, 14, 15
DESCRIPTION
—
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2014 Maxim Integrated Products, Inc. │ 22
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