DATASHEET
ISL91127IR
High Efficiency Buck-Boost Regulator with 4.5A Switches
The
ISL91127IR
is a high-current buck-boost switching
regulator for systems using new battery chemistries. It uses
Intersil’s proprietary buck-boost algorithm to maintain voltage
regulation while providing excellent efficiency and very low
output voltage ripple when the input voltage is close to the
output voltage.
The ISL91127IR is capable of delivering at least 2A continuous
output current (V
OUT
= 3.3V) over a battery voltage range of
2.5V to 4.35V. This maximizes the energy utilization of
advanced single-cell Li-ion battery chemistries that have
significant capacity left at voltages below the system voltage.
Its fully synchronous low ON-resistance, 4-switch architecture
and a low quiescent current of only 30µA optimize efficiency
under all load conditions.
The ISL91127IR supports stand-alone applications with a fixed
3.3V or 3.5V output voltage or adjustable output voltage with
an external resistor divider. Output voltages as low as 1.0V or
as high as 5.2V are supported.
The ISL91127IR is available in a 20 Ld, 0.5mm pitch QFN
(4mmx4mm) package. The 2.5MHz switching frequency
further reduces the size of external components.
FN8859
Rev 1.00
August 3, 2016
Features
• Accepts input voltages above or below regulated output
voltage
• Automatic and seamless transitions between buck and
boost modes
• Input voltage range: 1.8V to 5.5V
• Output current: up to 2A (PVIN = 2.5V, V
OUT
= 3.3V)
• High efficiency: up to 96%
• 30µA quiescent current maximizes light-load efficiency
• 2.5MHz switching frequency minimizes external component
size
• Fully protected for short-circuit, over-temperature and
undervoltage
• 20 Ld 4mmx4mm QFN package
Applications
• Handheld and battery powered consumer and medical
devices
• Brownout free system voltage for smartphones and tablet
PCs
• Wireless communication devices
• 2G/3G/4G RF power amplifiers
Related Literature
•
UG080,
“ISL91127IRN-EVZ, ISL91127IR2A-EVZ,
ISL91127IRA-EVZ Evaluation Boards User Guide”
100
ISL91127IRNZ
V
IN =
1.8V TO 5.5V
C
1
10µF
EFFICIENCY (%)
PVIN
LX1
L
1
1µH
LX2
VOUT
FB
V
OUT
= 3.3V
C
2
2x22µF
95
90
85
VIN = 2.5V
80
75
70
1
10
100
1000
LOAD CURRENT (mA)
VIN = 3.3V
VIN = 3.6V
VIN = 4V
VIN
EN
MODE
SGND PGND
FIGURE 1. TYPICAL APPLICATION: V
OUT
= 3.3V
FIGURE 2. EFFICIENCY: V
OUT
= 3.3V, T
A
= +25°C
FN8859 Rev 1.00
August 3, 2016
Page 1 of 12
ISL91127IR
Block Diagram
LX1
4
LX2
5
1
2
6
PVIN
7
8
9
GATE
DRIVE RS
AND
ANTI-SHOOT
THRU
Q1
Q4
17
18
VOUT
19
REVERSE
CURRENT
20
EN
11
EN
Q2
VIN 10
Q3
-
+
VREF
EN
VIN
MONITOR
3
PGND
THE RMAL
SHUTDOWN
VOUT
CLAMP
CURRENT
DETECT
13
SGND
14
CONTROL
EN
12
MODE
16
NC
EN
OSC
ERROR
AMP
ADJ
OUTPUT
15
FIX ED
OUTPUT
FB
COMP
+
-
-
+
REF
VOLTAGE
PROG.
FIGURE 3. BLOCK DIAGRAM
FN8859 Rev 1.00
August 3, 2016
Page 2 of 12
ISL91127IR
Pin Configuration
ISL91127IR
(20 LD, 4x4 QFN)
TOP VIEW
VOUT
VOUT
VOUT
VOUT
Pin Descriptions
PIN #
6, 7, 8, 9
4, 5
PIN NAMES
PVIN
LX1
PGND
LX2
VOUT
MODE
DESCRIPTION
Power input. Range: 1.8V to 5.5V. Connect
2x10μF capacitors to PGND.
Inductor connection, input side
Power ground for high switching current
Inductor connection, output side
Buck-boost regulator output. Connect
2x22μF capacitors to PGND.
Logic input, HIGH for auto PFM mode. LOW
for forced PWM operation. Also, this pin can
be used with an external clock sync input.
Range: 2.75MHz to 3.25MHz.
Supply input. Range: 1.8V to 5.5V.
Logic input, drive HIGH to enable device.
Analog ground pin
Voltage feedback pin
No connect pin
Thermal pad, connect to PGND
NC
3
1, 2
15 FB
14 SGND
20
LX2
LX2
PGND
LX1
LX1
1
2
3
4
5
6
PVIN
19
18
17
16
17, 18, 19,
20
12
EPAD
13 SGND
12 MODE
11 EN
10
11
13, 14
15
16
VIN
EN
SGND
FB
NC
EPAD
7
PVIN
8
PVIN
9
PVIN
10
VIN
Ordering Information
PART NUMBER
(Notes
1, 2, 3)
ISL91127IRNZ-T
ISL91127IRNZ-T7A
ISL91127IRAZ-T
ISL91127IRAZ-T7A
ISL91127IRN-EVZ
ISL91127IRA-EVZ
NOTES:
1. Please refer to
TB347
for details on reel specifications.
2. 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.
3. For Moisture Sensitivity Level (MSL), please see product information page for
ISL91127IR.
For more information on MSL please see techbrief
TB363.
PART
MARKING
1127N
1127N
1127A
1127A
OUTPUT VOLTAGE
(V)
3.3
3.3
ADJ
ADJ
TEMP RANGE
(°C)
-40 to +85
-40 to +85
-40 to +85
-40 to +85
TAPE AND REEL
(UNITS)
6k
250
6k
250
PACKAGE
(RoHS COMPLIANT)
20 Ld 4x4 QFN
20 Ld 4x4 QFN
20 Ld 4x4 QFN
20 Ld 4x4 QFN
PKG.
DWG. #
L20.4x4C
L20.4x4C
L20.4x4C
L20.4x4C
Evaluation Board for ISL91127IRNZ
Evaluation Board for ISL91127IRAZ
TABLE 1. KEY DIFFERENCES BETWEEN FAMILY OF PARTS
PART NUMBER
ISL91127
ISL91127IR
ISL91128
BUCK-BOOST
REGULATION
Yes
Yes
Yes
BYPASS
No
No
Yes
VSEL
No
No
No
I
2
C AND DVS
No
No
Yes
PACKAGE
WLCSP
QFN
WLCSP
NOTE: For the full family of ISL911xx buck-boost regulators, please visit
intersil.com/isl911xx-buck-boost-regulators.
FN8859 Rev 1.00
August 3, 2016
Page 3 of 12
ISL91127IR
Absolute Maximum Ratings
PVIN, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.5V
LX1, LX2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.5V
FB (Adjustable Version) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 2.7V
FB (Fixed V
OUT
Versions) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.5V
GND, PGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 0.3V
All Other Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.5V
ESD Rating
Human Body Model (Tested per JS-001-2010) . . . . . . . . . . . . . . . . .2.5kV
Machine Model (Tested per JESD22-A115C) . . . . . . . . . . . . . . . . . 250V
Charged Device Model (Tested per JS-002-2014) . . . . . . . . . . . . . . . 1kV
Latch-Up (Tested per JESD-78B; Class 2, Level A) . . . . . . . . . . . . . . 100mA
Thermal Information
Thermal Resistance (Typical)
JA
(°C/W)
JC
(°C/W)
20 Ld 4x4 QFN Package (Notes
4, 5).
. . . .
40
5
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .+125°C
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see
TB493
Recommended Operating Conditions
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Supply Voltage Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8V to 5.5V
Maximum Load Current
V
IN
= 2.5V V
OUT
= 3.3V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2ADC
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:
4.
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
5. For
JC
, the “case temp” location is the center of the exposed metal pad on the package underside.
Analog Specifications
SYMBOL
POWER SUPPLY
V
IN
V
UVLO
Input Voltage Range
V
IN
= V
PVIN
= V
EN
= 3.6V, V
OUT
= 3.3V, L
1
= 1µH, C
1
= 10µF, C
2
= 2x22µF, T
A
= +25°C. Boldface limits apply across
the operating temperature range, -40°C to +85°C and input voltage range (1.8V to 5.5V) unless specified otherwise.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
(Note
6)
(Note
7)
(Note
6)
UNIT
1.8
Rising
Falling
1.55
1.725
1.65
30
0.05
5.5
1.795
V
V
V
V
IN
Undervoltage Lockout Threshold
I
VIN
I
SD
V
IN
Supply Current
V
IN
Supply Current, Shutdown
PFM mode, 1.8V
≤
V
IN
≤
5V, no external load on V
OUT
(Note
8)
EN = GND, V
IN
= 3.6V
55
1.00
µA
µA
OUTPUT VOLTAGE REGULATION
V
OUT
Output Voltage Range
Output Voltage Accuracy
ISL91127IIAZ, I
OUT
= 100mA, V
IN
= 3.6V
V
IN
= 3.7V, V
OUT
= 3.3V, I
OUT
= 0mA, PWM mode
V
IN
= 3.7V, V
OUT
= 3.3V, I
OUT
= 1mA, PFM mode
V
FB
I
FB
V
OUT
/
V
IN
V
OUT
/
I
OUT
V
OUT
/
V
I
V
OUT
/
I
OUT
V
CLAMP
FB Pin Voltage Regulation
FB Pin Bias Current
Line Regulation, PWM Mode
Load Regulation, PWM Mode
Line Regulation, PFM Mode
Load Regulation, PFM Mode
Output Voltage Clamp
Output Voltage Clamp Hysteresis
For adjustable output version, V
IN
= 3.6V
For adjustable output version
I
OUT
= 500mA, V
OUT
= 3.3V, V
IN
step from 2.3V to 5.5V
V
IN
= 3.7V, V
OUT
= 3.3V, I
OUT
step from 0mA to 1000mA
I
OUT
= 100mA, V
OUT
= 3.3V, V
IN
step from 2.3V to 5.5V
V
IN
= 3.7V, V
OUT
= 3.3V, I
OUT
step from 0mA to 100mA
Rising
5.25
400
±5
±0.005
±12.5
±0.4
5.95
1.0
-2
-3
0.783
0.800
5.2
+2
+4
0.813
20
V
%
%
V
nA
mV/V
mV/mA
mV/V
mV/mA
V
mV
FN8859 Rev 1.00
August 3, 2016
Page 4 of 12
ISL91127IR
Analog Specifications
SYMBOL
V
IN
= V
PVIN
= V
EN
= 3.6V, V
OUT
= 3.3V, L
1
= 1µH, C
1
= 10µF, C
2
= 2x22µF, T
A
= +25°C. Boldface limits apply across
the operating temperature range, -40°C to +85°C and input voltage range (1.8V to 5.5V) unless specified otherwise. (Continued)
PARAMETER
TEST CONDITIONS
TYP
MAX
MIN
(Note
6)
(Note
7)
(Note
6)
UNIT
DC/DC SWITCHING SPECIFICATIONS
f
SW
t
ONMIN
I
PFETLEAK
I
NFETLEAK
Oscillator Frequency
Minimum On-Time
LX1 Pin Leakage Current
LX2 Pin Leakage Current
V
IN
= 3.6V
V
IN
= 3.6V
-1
-1
2.1
2.5
80
1
1
2.9
MHz
ns
µA
µA
SOFT-START AND SOFT DISCHARGE
t
SS
Soft-Start Time
Time from when EN signal asserts to when output
voltage ramp starts.
Time from when output voltage ramp starts to when
output voltage reaches 95% of its nominal value with
device operating in buck mode.
V
IN
= 4V, V
OUT
= 3.3V, I
O
= 200mA
Time from when output voltage ramp starts to when
output voltage reaches 95% of its nominal value with
device operating in boost mode.
V
IN
= 2V, V
OUT
= 3.3V, I
O
= 200mA
r
DISCHG
V
OUT
Soft-Discharge ON-Resistance
EN < V
IL
1
1
ms
ms
2
ms
120
Ω
POWER MOSFET
r
DSON_P
r
DSON_N
I
PK_LMT
P-Channel MOSFET ON-Resistance
N-Channel MOSFET ON-Resistance
V
IN
= 3.6V, I
O
= 200mA
V
IN
= 3.6V, I
O
= 200mA
3.7
32
37
4.5
5
mΩ
mΩ
A
P-Channel MOSFET Peak Current Limit V
IN
= 3.6V
PFM/PWM TRANSITION
Load Current Threshold, PFM to PWM
Load Current Threshold, PWM to PFM
Thermal Shutdown
Thermal Shutdown Hysteresis
LOGIC INPUTS
I
LEAK
V
IH
V
IL
NOTES:
6. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested.
7. Typical values are for T
A
= +25°C and V
IN
= 3.6V.
8. Quiescent current measurements are taken when the output is not switching.
Input Leakage
Input HIGH Voltage
Input LOW Voltage
V
IN
= 3.6V
V
IN
= 3.6V
V
IN
= 3.6V
1.4
V
IN
= 3.6V, V
OUT
= 3.3V
V
IN
= 3.6V, V
OUT
= 3.3V
200
75
155
30
mA
mA
°C
°C
0.05
1
µA
V
0.4
V
FN8859 Rev 1.00
August 3, 2016
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