DATASHEET
ISL97701
Boost Regulator with Integrated Schottky and Input Disconnect Switch
The ISL97701 represents a high efficiency boost converter
with integrated boost FET, boost diode and input disconnect
FET.
With an input voltage of 2.3V to 5.5V the ISL97701 has an
output capability of up to 50mA at 18V using integrated
500mA switches. Efficiencies are up to 87%. The
integrated protection FET is used to disconnect the boost
inductor from the input supply whenever an output fault
condition is detected, or when the device is disabled. This
gives 0 output current in the disabled mode, compared to
standard boost converters where current can still flow when
the device is disabled.
The ISL97701 comes in the 10 Ld 3x3 DFN package and is
specified for operation over the -40°C to +85°C temperature
range.
FN6474
Rev 1.00
February 22, 2008
Features
• Up to 87% efficiency
• 2.3V to 5.5V input
• Up to 28V output
• 50mA at 18V
• Integrated boost Schottky diode
• Input voltage disconnect switch
• Synchronization input
• Chip enable
• 10 Ld 3x3 DFN package
• Pb-free (RoHS compliant)
Ordering Information
PART
NUMBER
(Note)
ISL97701IRZ
ISL97701IRZ-T7*
ISL97701IRZ-T13*
PART
MARKING
977 01IRZ
977 01IRZ
977 01IRZ
PACKAGE
(Pb-free)
10 Ld 3x3 DFN
10 Ld 3x3 DFN
10 Ld 3x3 DFN
PKG.
DWG. #
MDP0047
MDP0047
MDP0047
Applications
• OLED display power
• LED display power
• Adjustable power supplies
Typical Application Diagram
L
1
6.8µH
VDDOUT
2.3V TO 5.5V
C
0
5µF
NEN
NSYNC
LX
VDD
OSCILLATOR
AND
CONTROL
VOUT
V
DD
+2V TO 30V
C
1
3.3µF
R
1
390k
*Please refer to TB347 for details on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets; molding compounds/die attach
materials and 100% matte tin plate PLUS ANNEAL - e3 termination
finish, which is RoHS compliant and compatible with both SnPb and
Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J STD-020.
Pinout
ISL97701
(10 LD 3X3 DFN)
TOP VIEW
GND 1
VDDOUT 2
VDD 3
NSYNC 4
FB 5
THERMAL
PAD
10 LX
9 VOUT
8 NEN
7 GND
6 NC
GND
FB
R
2
39k
NOTE: VOUT = (390k + 39k)/39k*1.15V = 12.65V
FN6474 Rev 1.00
February 22, 2008
Page 1 of 11
ISL97701
Block Diagram
VDD
SYNCHRONIZATION
SIGNAL DETECTOR
1
OSCILLATOR
MUX
0
CLK
START
OVER-TEMPERATURE
DETECTOR
UNDERVOLTAGE
DETECTOR
OVERCURRENT
DETECTOR (DC)
S2
VDD
NSYNC
VDD
NEN
GND
RESTART DISABLE AND WAIT
STATE MACHINE
(DEFAULT SEQUENCE)
1. SOFT INRUSH
2. VDD
OUT
ENABLE
3. SOFT BOOST 25
4. SOFT BOOST 50
5. SOFT BOOST 75
6. NORMAL
VDDOUT
2
OVER-
VOLTAGE
DETECTOR
VOUT
-
ERROR
AMP
+
FB
VOLTAGE
REFERENCE
ISL97701
SLOPE
COMPENSATION
RAMP-GENERATOR
+
As
-
+
Av
½
-
+
Ai
-
EN
CONTROL LOGIC
-PWM TIMING
-CURRENT LIMIT
-PULSE SKIPPING
GATE
DRIVER
CURRENT
LIMIT
COMPARATOR
LX
C
COMP
CLAMP
RSENSE
GND
FIGURE 1. ISL97701 BLOCK DIAGRAM
FN6474 Rev 1.00
February 22, 2008
Page 2 of 11
ISL97701
Absolute Maximum Ratings
(T
A
= +25°C)
VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V
V
OUT
to GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 31V
LX to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
OUT
+ 1V
VDDOUT, NSYNC, FB, NEN
to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VDD + 0.3V
Continuous Current in VDD, GND, VDDOUT, LX . . . . . . . . . 650mA
Continuous Current in NSYNC, FB, NEN . . . . . . . . . . . . . . . . 10mA
Thermal Information
Thermal Resistance (Typical, Notes 1, 2)
JA
(°C/W)
JC
(°C/W)
10 Ld 3x3 DFN Package . . . . . . . . . . .
48
7
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Ambient Operating Temperature (T
A
) . . . . . . . . . . . .-40°C to +85°C
Operating Junction Temperature (T
J
) . . . . . . . . . . . . . . . . . . +125°C
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . +130°C
Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.
NOTES:
1.
JA
is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379.
2. For
JC
, the “case temp” location is the center of the exposed metal pad on the package underside.
Electrical Specifications
PARAMETER
SUPPLY
V
DD
I
DIS
V
DD
= 3.6V, GND = NEN = 0V, NSYNC = V
DD
, R
1
= 390k, R
2
= 39k, L = 10µH, T
A
= -40°C to +85°C unless
otherwise stated.
CONDITION
MIN
TYP
MAX
UNIT
DESCRIPTION
Supply Operating Voltage Range
Supply Current when Disabled
NEN = VDD
2.3
0.1
5.5
3
V
µA
LOGIC INPUTS – NEN, NSYNC
R
UP
I
IL
VHI
VLO
Pull-up Resistor
Leakage Current when Disabled
Logic High Threshold
Logic Low Threshold
Enabled, Input at GND
Disabled, Input at GND
150
-1
1.8
0.7
250
350
1
k
µA
V
V
POWER-ON RESET – VDD
V
RES_ON
V
RES_OFF
Power-On Reset Threshold
Power-Off Threshold
V
DD
rising
V
DD
falling
1.9
2.2
2
2.3
V
V
LX OUTPUT DRIVER
f
OSC
f
SYNC
t
ON-MIN
t
OFF-MIN
r
ON
I
LEAK
I
PEAK
LX Switching Frequency with Internal
Oscillator
LX Switching Frequency when
Externally Synchronized at NSYNC
Minimum On-Time
Minimum Off-time
( Maximum Duty Cycle)
LX ON-Resistance
LX Leakage Current
LX Peak Current Limit
FB = 0V, I(LX) > Ilim(LX)
FB = 0V, I(LX) < Ilim(LX)
I(LX) = 100mA
NEN = VDD, V(LX) = 30V
t > 8.32ms (end of soft-start)
0.9
1
f
(NSYNC)
60
60
0.4
1
1200
5
ns
ns
µA
mA
1.1
MHz
SCHOTTKY DIODE – LX, V
OUT
V
DIODE
Forward Voltage from LX to V
OUT
I = 10mA, T
A
= +25°C
I = 10mA, T
A
= -40°C to +85°C
0.4
0.3
0.5
0.5
0.6
0.7
V
V
FN6474 Rev 1.00
February 22, 2008
Page 3 of 11
ISL97701
Electrical Specifications
PARAMETER
FEEDBACK INPUTS
Vref
FB
Input Reference Voltage on FB
T
A
= +25°C
T
A
= -40°C to +85°C
I
FB
R
FB
Input Current in FB
FB Pull-Down Switch Resistance
FB = 1.3V
I
FB
= 10mA
1.13
1.12
-0.2
15
1.15
1.15
1.17
1.18
0.2
25
V
V
µA
V
DD
= 3.6V, GND = NEN = 0V, NSYNC = V
DD
, R
1
= 390k, R
2
= 39k, L = 10µH, T
A
= -40°C to +85°C unless
otherwise stated.
(Continued)
CONDITION
MIN
TYP
MAX
UNIT
DESCRIPTION
SYNCHRONIZATION INPUT – NSYNC
f
NSYNC
td
NSYNC
External Sync Frequency Range
NSYNC Falling Edge to LX Falling Edge
Delay
f
NSYNC
= 600kHz
600
80
1400
100
kHz
ns
OVERVOLTAGE DETECTOR - V
OUT
V
OUT
Overvoltage Threshold
FB = GND
31
35
V
OVERCURRENT DETECTOR
I
OCTVDDOUT
Overcurrent Threshold
t > 2.048ms, DC current
800
mA
OVER-TEMPERATURE DETECTOR
t
OFF
t
ON
Shut-Down Temperature Threshold
Turn-On Temperature Threshold
T rising
T falling
135
100
°C
°C
FAULT SWITCH – VDD, VDDOUT
r
ONFS
Ileak
VDDOUT
I
SS_VDDOUT
REGULATION
ACC
Output Voltage Accuracy, Assuming
Resistor Divider Tolerances of 0.1% or
Better
Load Regulation
Line Regulation
I
OUT
= 10mA, T
A
= +25°C
I
OUT
= 10mA, T
A
= -40°C to +85°C
I
OUT
= 0mA to 50mA
V
DD
= 3.6V to 2.6V, I
OUT
= 30mA
-1.5
-2.5
0.05
0.1
1.5
2.5
%
%
%
%/V
ON-Resistance from VDD to VDDOUT
Leakage Current
Soft Inrush Current Source at VDDOUT
I
OUT
= 50mA, t > 2.048ms
V
DDOUT
= 0V
V
DD
- V
DDOUT
= 0.5V, t
ON
< 2.048ms
0.2
0.01
50
3
µA
mA
V
OUT
/I
OUT
V
OUT
/V
DD
FN6474 Rev 1.00
February 22, 2008
Page 4 of 11
ISL97701
Typical Performance Curves
90
4.2V
85
EFFICIENCY (%)
EFFICIENCY (%)
85
90
4.2V
80
2.7V
75
3.6V
80
2.7V
75
3.6V
70
70
65
65
0
50
100
150
LOAD CURRENT (mA)
0
50
I
OUT
(mA)
100
150
FIGURE 2. EFFICIENCY vs LOAD CURRENT (V
OUT
= 18.3V)
L = 10µH (CDRH4D28C-100NC) C = 6.6µF
FIGURE 3. EFFICIENCY vs I
OUT
(V
OUT
= 18.3V)
L = 6.8µH (TDK RLF7030) C = 6.6µF
90
4.2V
85
EFFICIENCY (%)
3.6V
2.7V
EFFICIENCY (%)
90
4.2V
85
3.6V
2.7V
80
80
75
75
70
70
65
0
50
100
I
OUT
(mA)
150
200
65
0
50
100
I
OUT
(mA)
150
200
FIGURE 4. EFFICIENCY vs I
OUT
(V
OUT
= 12.6V)
L = 6.8µH (TDK RLF7030) C = 6.6µF
FIGURE 5. EFFICIENCY vs I
OUT
(V
OUT
= 12.7V)
L = 10µH (CDRH4D28C-100NC) C = 6.6µF
V(NEN)
V(NEN)
V(V
OUT
)
V(V
OUT
)
I(V
DD
)
I(V
DD
)
FIGURE 6. START-UP TO 12V (V
DD
= 3.6V, R
L
= 360)
FIGURE 7. START-UP TO 18V (V
DD
= 3.6V, R
L
= 360)
FN6474 Rev 1.00
February 22, 2008
Page 5 of 11
