Datasheet

DATASHEET
High Performance 1A LDO
ISL80510
Features
The ISL80510 is a single output Low Dropout voltage regulator
(LDO) capable of sourcing up to 1A output current. This LDO
operates from input voltages of 2.2V to 6V. The output voltage
of ISL80510 can be programmed from 0.8V to 5.5V.
• ±1.8% VOUT accuracy guaranteed over line, load and
TJ = -40°C to +125°C
A submicron BiCMOS process is utilized for this product family
to deliver the best in class analog performance and overall
value. This CMOS LDO consumes significantly lower quiescent
current as a function of load compared to bipolar LDOs, which
translates into higher efficiency and packages with smaller
footprints.
State-of-the-art internal compensation achieves a very fast
load transient response and excellent PSRR. The ISL80510
provides an output accuracy of ±1.8% VOUT accuracy over all
load, line and temperature variation (TJ = -40°C to +125°C).
An external capacitor on the soft-start pin provides an
adjustable soft starting of the output voltage ramp to control
the inrush current. The ENABLE feature allows the part to be
placed into a low quiescent current shutdown mode.
Table 1 shows the differences between the ISL80510 and
others in its family.
• Very low 130mV dropout voltage at VOUT = 2.5V
• Stable with a 4.7µF output ceramic capacitor
• Very fast transient response
• Programmable output soft-start time
• Excellent PSRR over wide frequency range
• Current limit protection
• Thermal shutdown function
• Available in an 8 Ld DFN package
• Pb-free (RoHS compliant)
Applications
• Noise-sensitive instrumentation systems
• Post regulation of switched mode power supplies
• Industrial systems
• Medical equipment
• Telecommunications and networking equipment
TABLE 1. KEY DIFFERENCES BETWEEN FAMILY OF PARTS
• Servers
PART NUMBER
MAX OUTPUT CURRENT
ISL80510
1.0A
ISL80505
0.5A
• Hard disk drives (HD/HDD)
ISL80510
VIN
1
8
VIN
CIN
2
7
SS
CSS
ENABLE
80
EPAD
6
FB
4
70
VOUT
3
5
VOUT
VOUT
GND
R1
COUT
CPB
(optional)
R2
IOUT = 0.6A
60
PSRR (dB)
VIN
50
40
30
20
10
VIN = 2.3V
VOUT = 1.8V
COUT = 10µF
CPB= 10nF
R1 = 2.61kΩ
R2 = 1kΩ
0
100
FIGURE 1. TYPICAL APPLICATION CIRCUIT
July 28, 2015
FN8767.0
1
1k
IOUT = 1A
10k
FREQUENCY (Hz)
IOUT = 0.2A
100k
1M
FIGURE 2. PSRR
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2015. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ISL80510
Block Diagram
VIN
REFERENCE
+
SOFT-START
ENABLE
CONTROL
LOGIC
THE RMAL
SENSO R
+
EA
FET DRIV ER
WITH CURRE NT
LIMIT
VOUT
SS
FB
GND
FIGURE 3. BLOCK DIAGRAM
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
PART
MARKING
ISL80510IRAJZ
0510
ISL80510EVAL1Z
Evaluation Board
TEMP RANGE
(°C)
-40 to +125
PACKAGE
(RoHS Compliant)
8 Ld 3x3 DFN
PKG
DWG. #
L8.3X3J
NOTES:
1. Add “-T*” for Tape and Reel. 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 device information page for ISL80510. For more information on MSL please see Technical Brief
TB363.
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ISL80510
Pin Configuration
ISL80510
(8 LD 3x3 DFN)
TOP VIEW
VOUT 1
8 VIN
VOUT 2
EPAD
FB 3
GND 4
7 VIN
6 SS
5 ENABLE
Pin Descriptions
PIN NUMBER
PIN NAME
1, 2
VOUT
3
FB
4
GND
5
ENABLE
6
SS
External capacitor on this pin adjusts start-up ramp and controls inrush current.
7, 8
VIN
Input supply; A minimum of 4.7µF X5R/X7R input capacitor is required for proper operation. See “External
Capacitor Requirements” on page 10 for more details.
-
EPAD
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DESCRIPTION
Regulated output voltage. A minimum 4.7µF X5R/X7R output capacitor is required for stability. See “External
Capacitor Requirements” on page 10 for more details.
This pin is the input to the control loop error amplifier and is used to set the output voltage of the LDO.
Ground
VIN independent chip enable. TTL and CMOS compatible.
EPAD at ground potential; It is recommended to solder the EPAD to the ground plane.
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ISL80510
Absolute Maximum Ratings
Thermal Information
VIN Relative to GND (Note 4) . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.5V
VOUT Relative to GND (Note 4) . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.5V
ENABLE, FB, SS
Relative to GND (Note 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.5V
ESD Rating
Human Body Model (Tested per JESD22-A114F) . . . . . . . . . . . . . . .2.5kV
Machine Model (Tested per JESD22-A115C) . . . . . . . . . . . . . . . . . 250V
Charge Device Model (Tested per JESD22-C101C). . . . . . . . . . . . . . . 2kV
Latch-up (Tested per JESD78C, Class 2, Level A) . . . . . ±100mA at +85°C
Thermal Resistance (Typical)
JA (°C/W) JC (°C/W)
8 Ld DFN Package (Notes 5, 6). . . . . . . . . .
48
7
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+150°C
Pb-free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see TB493
Recommended Operating Conditions (Notes 7, 8)
Junction Temperature Range (TJ) (Note 7) . . . . . . . . . . . .-40°C to +125°C
VIN Relative to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2V to 6V
VOUT Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .800mV to 5.5V
ENABLE, FB, SS relative to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to 6V
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. Absolute maximum voltage rating is defined as the voltage applied for a lifetime average duty cycle above 6V of 1%.
5. 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.
6. For JC, the “case temp” location is the center of the exposed metal pad on the package underside.
7. Extended operation at these conditions may compromise reliability. Exceeding these limits will result in damage. Recommended operating conditions
define limits where specifications are guaranteed.
8. Electromigration specification defined as lifetime average junction temperature of +110°C where max rated DC current = lifetime average current.
Electrical Specifications
Unless otherwise noted, 2.2V < VIN < 6V, VOUT = 0.5V, TJ = +25°C. Applications must follow thermal
guidelines of the package to determine worst case junction temperature. Please refer to “Applications Information” on page 10 and Tech Brief TB379.
Boldface limits apply across the operating temperature range, -40°C to +125°C.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
(Note 9)
TYP
MAX
(Note 9)
UNIT
491
500
509
mV
DC CHARACTERISTICS
Feedback Pin Voltage
VFB
2.2V < VIN < 6V; 0A < ILOAD < 1A
1
µA
Line Regulation
(VOUT(LOW LINE) VOUT(HIGH
LINE))/VOUT(LOW LINE)
VFB = 0.5V
VIN = 2.2V to 6V; ILOAD = 100mA
-0.9
0.9
%
Load Regulation
(VOUT(NO LOAD) VOUT(FULL
LOAD))/VOUT(NO LOAD)
VIN = 2.2V; ILOAD = 0A to 1A
-0.9
0.9
%
Feedback Input Current
Ground Pin Current
IQ
Ground Pin Current in Shutdown
ISHDN
0.01
ILOAD = 0A, VIN = 2.2V
2.2
4.6
mA
ILOAD = 1A, VIN = 2.2V
2.8
5.7
mA
ENABLE Pin = 0V, VIN = 6V
0.2
12
µA
130
212
mV
1.75
2.15
A
Dropout Voltage (Note 10)
VDO
ILOAD = 1A, VOUT = 2.5V
Output Short-circuit Current
OCP
VOUT = 0V
1.35
Thermal Shutdown Temperature
TSD
160
°C
Thermal Shutdown Hysteresis
TSDn
30
°C
f = 1kHz, ILOAD = 1A; VIN = 2.2V; VOUT = 1.8V
48
dB
f = 120Hz, ILOAD = 1A; VIN = 2.2V; VOUT = 1.8V
58
dB
VIN = 2.2V; VOUT = 1.8V; ILOAD = 1A,
BW = 100Hz < f < 100kHz
75
µVRMS
AC CHARACTERISTICS
Input Supply Ripple Rejection
PSRR
Output Noise Voltage
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ISL80510
Electrical Specifications
Unless otherwise noted, 2.2V < VIN < 6V, VOUT = 0.5V, TJ = +25°C. Applications must follow thermal
guidelines of the package to determine worst case junction temperature. Please refer to “Applications Information” on page 10 and Tech Brief TB379.
Boldface limits apply across the operating temperature range, -40°C to +125°C. (Continued)
MIN
(Note 9)
TYP
MAX
(Note 9)
UNIT
Turn-on Threshold
0.5
0.8
1
V
Hysteresis
10
80
200
mV
PARAMETER
SYMBOL
TEST CONDITIONS
ENABLE PIN CHARACTERISTICS
ENABLE Pin Turn-on Delay
COUT = 4.7µF, ILOAD = 1A
ENABLE Pin Leakage Current
VIN = 6V, ENABLE = 3V
100
µs
1
µA
SOFT-START CHARACTERISTICS
IPD
SS Pin Currents (Note 11)
VIN = 3.5V, ENABLE = 0V, SS = 1V
ICHG
0.5
1
1.3
mA
-3.3
-2
-0.8
µA
NOTES:
9. 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.
10. Dropout is defined as the difference in supply VIN and VOUT when the output is below its nominal regulation.
11. IPD is the internal pull-down current that discharges the external SS capacitor on disable. ICHG is the current from the SS pin that charges the external
SS capacitor during start-up.
Typical Operating Performance
IL = 0A.
Unless otherwise noted: VIN = 2.2V, VOUT = 1.8V, CIN = COUT = 10µF, TJ = +25°C,
100
180
140
+85°C
120
100
+25°C
80
60
0°C
40
20
0
0
0.2
0.3
0.4
0.5
0.6
+125°C
80
70
+85°C
60
50
40
30
0°C
-40°C
0.7
0.8
0.9
0
2.2
1.0
2.5
2.8
3.1
OUTPUT CURRENT (A)
3.4 3.7 4.0 4.3 4.6
OUTPUT VOLTAGE (V)
4.9
5.2
5.5
FIGURE 5. DROPOUT vs OUTPUT VOLTAGE
FIGURE 4. DROPOUT vs OUTPUT CURRENT
180
180
160
IOUT = 1A
+125°C
160
+85°C
140
DROPOUT VOLTAGE (mV)
DROPOUT VOLTAGE (mV)
+25°C
20
10
-40°C
0.1
IOUT = 500mA
90
+125°C
DROPOUT VOLTAGE (mV)
DROPOUT VOLTAGE (mV)
160
VOUT = 2.5V
120
100
80
-40°C
60
0°C
+25°C
40
VOUT = 2.5V
140
120
IOUT = 1A
100
80
60
40
IOUT = 500mA
20
20
0
2.2
2.5
2.8
3.1
3.4 3.7 4.0 4.3 4.6
OUTPUT VOLTAGE (V)
4.9
FIGURE 6. DROPOUT vs OUTPUT VOLTAGE
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5
5.2
5.5
0
-40
-25
-10
5.0
20
35
50
65
80
95
110 125
TEMPERATURE (°C)
FIGURE 7. DROPOUT vs TEMPERATURE
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ISL80510
Typical Operating Performance
IL = 0A. (Continued)
Unless otherwise noted: VIN = 2.2V, VOUT = 1.8V, CIN = COUT = 10µF, TJ = +25°C,
3.0
3.0
2.5
2.5
+125°C
+85°C
GROUND CURRENT (mA)
GROUND CURRENT (mA)
IOUT = 0A
2.0
1.5
+25°C
-40°C
1.0
2.0
1.5
+25°C
1.0
-40°C
0.5
0.5
0
+125°C
+85°C
0
0.2
0.4
0.6
0.8
0
2.2
1.0
2.7
3.3
3.8
4.4
4.9
5.4
6.0
INPUT VOLTAGE (V)
OUTPUT CURRENT (A)
FIGURE 9. GROUND CURRENT vs INPUT VOLTAGE
FIGURE 8. GROUND CURRENT vs OUTPUT CURRENT
3.0
7
IOUT = 0A
6
SHUTDOWN CURRENT (µA)
GROUND CURRENT (mA)
2.5
2.0
1.5
1.0
0.5
5
VIN = 6V
4
VIN = 5V
3
VIN = 2.2V
2
VIN = 3V
0
-40
-25
-10
5.0
20
35
50
65
80
95
0
110 125
VIN = 4V
-40
-25
-10
5.0
1.0
0.7
0.6
EN FALLING THRESHOLD
0.4
0.3
0.2
0.1
0
-40
0.9
EN THRESHOLD VOLTAGE (V)
EN RISING THRESHOLD
0.5
50
65
80
95
110 125
1.0
VIN = 2.2V
0.8
35
FIGURE 11. SHUTDOWN CURRENT vs TEMPERATURE
FIGURE 10. GROUND CURRENT vs TEMPERATURE
0.9
20
TEMPERATURE (°C)
TEMPERATURE (°C)
EN THRESHOLD VOLTAGE (V)
VIN = 2.5V
1
SOLID LINE = RISING THRESHOLD
DOTTED LINE = FALLING THRESHOLD
0.8
0.7
0.6
0.5
0.4
0.3
+85°C
+25°C
+125°C
-40°C
0.2
0.1
-25
-10
5.0
20
35
50
65
80
95
TEMPERATURE (°C)
FIGURE 12. EN THRESHOLDS vs TEMPERATURE
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110 125
0
2.2
2.7
3.3
3.8
4.4
4.9
5.4
6.0
INPUT VOLTAGE (V)
FIGURE 13. EN THRESHOLDS vs INPUT VOLTAGE
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ISL80510
Typical Operating Performance
IL = 0A. (Continued)
Unless otherwise noted: VIN = 2.2V, VOUT = 1.8V, CIN = COUT = 10µF, TJ = +25°C,
2.0
1.854
1.8
1.836
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
1.6
+125°C
1.4
1.2
1.0
+85°C
0.8
0.6
+25°C
0.4
1.818
1.800
1.782
-40°C
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
1.746
6.0
0
0.2
INPUT VOLTAGE (V)
0.4
0.6
0.8
1.0
OUTPUT CURRENT (A)
FIGURE 14. OUTPUT VOLTAGE vs INPUT VOLTAGE
FIGURE 15. OUTPUT VOLTAGE vs OUTPUT CURRENT
1.854
1.854
IOUT = 10mA
IOUT = 0A
1.836
OUTPUT VOLTAGE (V)
1.836
OUTPUT VOLTAGE (V)
+125°C
-40°C
1.764
0.2
0
+85°C
+25°C
1.818
1.800
IOUT = 1A
1.782
1.764
+25°C
+85°C
1.818
1.800
+125°C
-40°C
1.782
1.764
1.746
-40
-25
-10
5.0
20
35
50
65
80
95
110 125
1.746
2.2
2.7
TEMPERATURE (°C)
FIGURE 16. OUTPUT VOLTAGE vs TEMPERATURE
3.3
3.8
4.4
4.9
INPUT VOLTAGE (V)
5.4
6.0
FIGURE 17. OUTPUT VOLTAGE vs INPUT VOLTAGE
2.2
OUTPUT VOLTAGE (V)
RLOAD = 3.6Ω
VIN = 2.2V
2.0
EN (2V/DIV)
1.8
1.6
SS (500mV/DIV)
VIN = 6V
1.4
VOUT (500mV/DIV)
1.2
1.0
-40
-25
-10
5.0
20
35
50
65
80
95
110 125
TEMPERATURE (°C)
FIGURE 18. CURRENT LIMIT vs TEMPERATURE
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ILOAD (500mA/DIV)
2ms/DIV
FIGURE 19. ENABLE START-UP (CSS = 10nF)
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ISL80510
Typical Operating Performance
IL = 0A. (Continued)
Unless otherwise noted: VIN = 2.2V, VOUT = 1.8V, CIN = COUT = 10µF, TJ = +25°C,
COUT = 10µF, CPB = 10nF
COUT = 4.7µF
VOUT (AC- COUPLED, 50mV/DIV)
VOUT (AC- COUPLED, 20mV/DIV)
10mA <-> 1A AT 2A/µs
10mA <-> 1A AT 2A/µs
ILOAD (1A/DIV)
ILOAD (1A/DIV)
200µs/DIV
200µs/DIV
FIGURE 20. LOAD TRANSIENT RESPONSE
FIGURE 21. LOAD TRANSIENT RESPONSE
COUT = 4.7µF, ILOAD = 10mA
COUT = 10µF, CPB = 10nF, ILOAD = 10mA
VOUT (AC- COUPLED, 10mV/DIV)
VOUT (AC- COUPLED, 10mV/DIV)
2.2V <-> 6V AT 1V/µs
VIN (2V/DIV)
VIN (2V/DIV)
2.2V <-> 6V AT 1V/µs
200µs/DIV
200µs/DIV
FIGURE 22. LINE TRANSIENT RESPONSE
FIGURE 23. LINE TRANSIENT RESPONSE
80
80
70
IOUT = 0.6A
70
IOUT = 0.2A
50
40
30
IOUT = 0.8A
IOUT = 1A
20
IOUT = 0.2A
IOUT = 0.6A
IOUT = 0.4A
60
PSRR (dB)
PSRR (dB)
60
IOUT = 0.4A
50
40
30
IOUT = 1A
IOUT = 0.8A
20
10
10
CPB = 10nF
0
100
1k
10k
100k
FREQUENCY (Hz)
FIGURE 24. PSRR vs FREQUENCY
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8
1M
0
100
VIN = 2.3V
CPB = 10nF
10k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 25. PSRR vs FREQUENCY
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ISL80510
Typical Operating Performance
Unless otherwise noted: VIN = 2.2V, VOUT = 1.8V, CIN = COUT = 10µF, TJ = +25°C,
IL = 0A. (Continued)
80
80
70
70
IOUT = 0.4A
50
IOUT = 0.2A
40
30
IOUT = 1A
20
10
IOUT = 0.2A
50
40
30
IOUT = 1A
IOUT = 0.8A
10
COUT = 4.7µF
1k
IOUT = 0.4A
20
IOUT = 0.8A
0
100
IOUT = 0.6A
60
IOUT = 0.6A
PSRR (dB)
PSRR (dB)
60
10k
FREQUENCY (Hz)
100k
COUT = 100µF
0
100
1k
1M
OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz)
FIGURE 26. PSRR vs FREQUENCY (COUT = 4.7µF)
10k
FREQUENCY (Hz)
100k
1M
FIGURE 27. PSRR vs FREQUENCY (COUT = 100µF)
10.00
IOUT = 1A
1.00
0.10
0.01
100
1k
10k
100k
FREQUENCY (Hz)
FIGURE 28. OUTPUT NOISE SPECTRAL DENSITY
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ISL80510
Applications Information
OUTPUT CAPACITOR
Input Voltage Requirements
The ISL80510 is a linear voltage regulator operating from 2.2V to
6V input voltage and regulates output voltage between 0.8V to
5.5V, a maximum 1A output current.
Due to the nature of an LDO, VIN must be some margin higher
than VOUT plus dropout at the maximum rated current of the
application if active filtering (PSRR) is expected from VIN to VOUT.
The generous dropout specification of this family of LDOs allows
applications to design a level of efficiency.
Enable Operation
The ENABLE turn-on threshold is typically 800mV with 80mV of
hysteresis. An internal pull-up or pull-down resistor to change
these values is available upon request. As a result, this pin must
not be left floating, and should be tied to VIN if not used. A 1kΩ to
10kΩ pull-up resistor is required for applications that use open
collector or open-drain outputs to control the ENABLE pin. The
ENABLE pin may be connected directly to VIN for applications
with outputs that are always on.
The ISL80510 applies state-of-the-art internal compensation to
keep the selection of the output capacitor simple for the
customer. Stable operation over full temperature, VIN range,
VOUT range and load extremes are guaranteed for all capacitor
types and values assuming a minimum of 4.7µF X5R/X7R is
used for local bypass on VOUT. This output capacitor must be
connected to the VOUT and GND pins of the LDO with PCB traces
no longer than 0.5cm.
There is a growing trend to use very low ESR Multilayer Ceramic
Capacitors (MLCC) because they can support fast load transients
and also bypass very high frequency noise from other sources.
However, the effective capacitance of MLCCs drops with applied
voltage, age and temperature. X7R and X5R dielectric ceramic
capacitors are strongly recommended as they typically maintain
a capacitance range within ±20% of nominal voltage over full
operating ratings of temperature and voltage.
Additional capacitors of any value in ceramic, POSCAP,
alum/tantalum electrolytic types may be placed in parallel to
improve PSRR at higher frequencies and/or load transient AC
output voltage tolerances.
Output Voltage
INPUT CAPACITOR
The output voltage can be set to be an external resistor divider
network. The values of resistors R1 and R2 can be calculated by
using Equation 1.
For proper operation, a minimum capacitance of 4.7µF X5R/X7R
is required at the input. This ceramic input capacitor must be
connected to the VIN and GND pins of the LDO with PCB traces no
longer than 0.5cm.
V OUT
R 1 = R 2   ---------------- – 1
 0.5

(EQ. 1)
Soft-start Operation
The soft-start circuit controls the rate at which the output voltage
rises up to regulation at power-up or LDO enable. This start-up
ramp time can be set by adding an external capacitor from the
SS pin to ground. An internal 2µA current source charges up the
CSS and the feedback reference voltage is clamped to the
voltage across it. The start-up time is set by Equation 2.
C SS x0.5
t start = -----------------------2A
(EQ. 2)
Equation 3 determines the CSS required for a specific start-up
inrush current, where VOUT is the output voltage, COUT is the total
capacitance on the output and IINRUSH is the desired inrush
current.
V OUT xC OUT x2A
C SS = ---------------------------------------------------I INRUSH x0.5V
(EQ. 3)
The external capacitor is always discharged to ground at the
beginning of start-up or enabling.
External Capacitor Requirements
External capacitors are required for proper operation. Careful
attention must be paid to the layout guidelines and selection of
capacitor type and value to ensure optimal performance.
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PHASE BOOST CAPACITOR (CPB)
A small phase boost capacitor, CPB, can be placed across the top
resistor, R1, in the feedback resistor divider network in order to
improve the AC performances of the LDO for the applications
where the output capacitor is 10µF or larger. For 10µF output
capacitor, the recommended CPB value can be calculated by
using Equation 4.
1
C PB = ----------------------------------2x6000xR 1
(EQ. 4)
This zero increases the crossover frequency of the LDO and
provides additional phase resulting in faster load transient
response
Power Dissipation and Thermals
The junction temperature must not exceed the range specified in
the “Recommended Operating Conditions (Notes 7, 8)” on
page 4. The power dissipation can be calculated by using
Equation 5:
P D =  V IN – V OUT   I OUT + V IN  I GND
(EQ. 5)
The maximum allowable junction temperature, TJ(MAX) and the
maximum expected ambient temperature, TA(MAX) determine the
maximum allowable power dissipation, as shown in Equation 6:
P D  MAX  =  T J  MAX  – T A    JA
(EQ. 6)
JA is the junction-to-ambient thermal resistance.
FN8767.0
July 28, 2015
ISL80510
For safe operation, ensure that the power dissipation PD,
calculated from Equation 5, is less than the maximum allowable
power dissipation PD(MAX).
.
IN
OUT
The DFN package uses the copper area on the PCB as a heatsink.
The EPAD of this package must be soldered to the copper plane
(GND plane) for effective heat dissipation. Figure 29 shows a curve
for the JA of the DFN package for different copper area sizes.
COUT
R1
49
ISL80510
CIN
EN
47
CPB
JA °C/W
45
R2
CSS
GND
43
FIGURE 30. EXAMPLE FOR PCB LAYOUT
41
39
37
2
4
6
8
10
12
14
16
18
20
22
24
EPAD-MOUNT COPPER LAND AREA ON PCB, mm2
FIGURE 29. 3mmx3mm-10 PIN DFN ON 4-LAYER PCB WITH
THERMAL VIAS JA vs EPAD-MOUNT COPPER LAND
AREA ON PCB
General PowerPAD Design
Considerations
The following is an example of how to use via’s to remove heat
from the IC.
Thermal Fault Protection
The power level and the thermal impedance of the package
(+48°C/W for DFN) determine when the junction temperature
exceeds the thermal shutdown temperature. In the event that the
die temperature exceeds around +160°C, the output of the LDO will
shut down until the die temperature cools down to about +130°C.
Current Limit Protection
The ISL80510 LDO incorporates protection against overcurrent due
to any short or overload condition applied to the output pin. The LDO
performs as a constant current source when the output current
exceeds the current limit threshold noted in the “Electrical
Specifications” table on page 4. If the short or overload condition is
removed from VOUT, then the output returns to normal voltage
regulation mode. In the event of an overload condition, the LDO may
begin to cycle on and off due to the die temperature exceeding
thermal fault condition and subsequently cooling down after the
power device is turned off.
FIGURE 31. PCB VIA PATTERN
A minimum of 4 vias evenly distributed to fill the thermal pad
footprint is recommended. Keep the vias small but not so small
that their inside diameter prevents solder wicking through the
holes during reflow.
Connect all vias to the ground plane. It is important the vias have
a low thermal resistance for efficient heat transfer. Do not use
“thermal relief” patterns to connect the vias. It is important to
have a complete connection of the plated through-hole to each
plane.
PC Board Layout
The performances of this LDO depend greatly on the care taken
in designing the PC board. The following are recommendations to
achieve optimum performance.
• A minimum capacitance of 4.7µF X5R/X7R ceramic input
capacitor must be placed to the VIN and GND pins of the LDO
with PCB traces no longer than 0.5cm.
• A minimum capacitance of 4.7µF X5R/X7R ceramic output
capacitor must be placed to the VOUT and GND pins of the LDO
with PCB traces no longer than 0.5cm.
• Connect the EPAD to the ground plane with low-thermal
resistance vias.
Figure 30 shows an example for 2-layer PCB layout. The bottom
layer is the ground plane
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FN8767.0
July 28, 2015
ISL80510
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you
have the latest revision.
DATE
REVISION
July 28, 2015
FN8767.0
CHANGE
Initial Release
About Intersil
Intersil Corporation is a leading provider of innovative power management and precision analog solutions. The company's products
address some of the largest markets within the industrial and infrastructure, mobile computing and high-end consumer markets.
For the most updated datasheet, application notes, related documentation and related parts, please see the respective product
information page found at www.intersil.com.
You may report errors or suggestions for improving this datasheet by visiting www.intersil.com/ask.
Reliability reports are also available from our website at www.intersil.com/support
For additional products, see www.intersil.com/en/products.html
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time
without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
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FN8767.0
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ISL80510
Package Outline Drawing
L8.3x3J
8 LEAD DUAL FLAT NO-LEAD PLASTIC PACKAGE
Rev 1 3/15
2X 1.950
3.00
B
0.15
8
5
3.00
(4X)
6X 0.65
A
1.64 +0.10/ - 0.15
6
PIN 1
INDEX AREA
4
8X 0.30
8X 0.400 ± 0.10
TOP VIEW
6
PIN #1 INDEX AREA
1
4
0.10 M C A B
2.38
+0.10/ - 0.15
BOTTOM VIEW
SEE DETAIL "X"
( 2.38 )
( 1.95)
0.10 C
Max 1.00
C
0.08 C
SIDE VIEW
( 8X 0.60)
(1.64)
( 2.80 )
PIN 1
C
0 . 2 REF
5
(6x 0.65)
0 . 00 MIN.
0 . 05 MAX.
( 8 X 0.30)
DETAIL "X"
TYPICAL RECOMMENDED LAND PATTERN
NOTES:
1.
Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
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3.
Unless otherwise specified, tolerance : Decimal ± 0.05
4.
Dimension applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
5.
Tiebar shown (if present) is a non-functional feature and may be
located on any of the 4 sides (or ends).
6.
The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
FN8767.0
July 28, 2015
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