DATASHEET
5A Single Channel High Efficiency DC/DC Step-Down
Power Module
ISL8205M
Features
The ISL8205M power module is a single channel synchronous
step-down complete power supply, capable of delivering up to
5A of continuous current. Operating from a single 2.6V to 5.5V
input power rail and integrating controller, power inductor and
MOSFETs, the ISL8205M only requires a few external
components to operate and is optimized for space constrained
and portable battery operated applications.
• 5A single channel complete power supply
- Integrates controller, MOSFETs and inductor
- Pin/function compatible with the 3A ISL8202M
• 2.6V to 5.5V input voltage range
• Adjustable output voltage range
- As low as 0.6V with ±1.6% accuracy over
line/load/temperature
- Up to 95% efficiency
Based on current mode PWM control scheme, the ISL8205M
provides a fast transient response and excellent loop stability
as well as a very low duty cycle with an adjustable output
voltage as low as 0.6V and better than 1.6% accuracy over line
and load conditions. Operation frequency is selectable through
an external resistor, with a 1.8MHz default setting, or may be
synchronized with an external clock signal up to 3.5MHz. The
ISL8205M also implements a selectable PFM mode to
improve light-load efficiency and a 100% duty cycle LDO mode
to extend battery life. A programmable soft-start reduces the
inrush current required from the input supply while an
automatic output discharge ensures a soft stop. Dedicated
enable pin and power-good flag allow for easy system power
rails sequencing.
• Default 1.8MHz current mode control operations
- 680kHz to 3.5MHz resistor adjustable
- External synchronization up to 3.5MHz
- Selectable light-load efficiency mode
- 100% duty cycle LDO mode
• Programmable soft-start
• Soft-stop output discharge
• Dedicated enable pin and power-good flag
• UVLO, over-temperature, overcurrent, overvoltage and
negative overcurrent protections
- Overcurrent/short-circuit hiccup mode
An array of protection features, including input Undervoltage
Lockout (UVLO), over-temperature, overcurrent/short-circuit
with hiccup mode, overvoltage and negative overcurrent,
guarantees safe operations under abnormal operating
conditions.
• 4.5mmx7.5mmx1.85mm 22 Ld QFN package
Applications
The ISL8205M is available in a compact RoHS compliant
22 Ld 4.5x7.5x1.85mm QFN package.
• DC to DC POL power module
Related Literature
• Portable equipment
• TB389, “PCB Land Pattern Design and Surface Mount
Guidelines for QFN Packages”
• Battery operated equipment
• µC/µP, FPGA and DSP power
100.0
ISL8205M
CIN
2x22µF
VIN
VOUT
EN
SW
PG
VSENSE
FB
FS
RFS
124k
90.0
COUT
2x22µF
COMP
SYNC
SS
EPAD
SGND
95.0
1.2V 5A
OUTPUT
PGND
RSET
100k
EFFICIENCY (%)
2.6V TO 5.5V
INPUT
85.0
80.0
75.0
Vout=1.2V, Fsw=1.6MHz PWM
Vout=1.2V, Fsw=1.6MHz PFM
Vout=3.3V, Fsw=3MHz PFM
Vout=3.3V, Fsw=3MHz PWM
70.0
CFF
820pF
65.0
60.0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
LOAD CURRENT (A)
FIGURE 1. TYPICAL APPLICATION DIAGRAM AT 5VIN, 1.2VOUT, 1.6MHz fSW, 5A
May 10, 2016
FN8755.1
1
FIGURE 2. EFFICIENCY vs LOAD 5VIN
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 2016. 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.
ISL8205M
Table of Contents
Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pin Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Typical Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Efficiency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Output Voltage Ripple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Load Transient Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Short-Circuit Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Overvoltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Power Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Derating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PWM Control Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PFM (SKIP) Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frequency Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Negative Current Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power-Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UVLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soft Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Synchronization Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Discharge Mode (Soft-Stop) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
100% Duty Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
15
15
15
15
16
16
16
16
16
16
16
16
16
Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming the Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended Switching Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Capacitor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Capacitor Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feed-Forward Capacitor Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Consideration and Current Derating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16
16
17
17
17
17
18
18
PCB Layout Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PCB Layout Pattern Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Vias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stencil Pattern Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reflow Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
20
20
20
20
20
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
About Intersil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
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ISL8205M
Functional Block Diagram
SS
COMP
FS
SYNC
18
16
13
SHUTDOWN
SOFTSTART
17
SHUTDOWN
EN
FB
15
BANDGAP
OSCILLATOR
VREF
COMP
EAMP
PWM/PFM LOGIC
CONTROLLER
PROTECTION
HS DRIVER
L
LS
DRIVER
19
11
VIN
21
SW
6
VOUT
9
SW
3
PGND
20
PGND
14
PGND
4
VSENSE
2
VSENSE
22
SGND
0.8V
FB
SLOPE
COMP
1
OV
CSA
51
OCP
UV
0.85 x VREF
ISET
THRESHOLD
SKIP
PG
12
1ms
DELAY
NEGATIVE CURRENT
SENSING
ZERO-CROSSING
SENSING
SCP
0.5V
100
SGND
PGND
SHUTDOWN
100k0.5%
FIGURE 3. FUNCTIONAL BLOCK DIAGRAM
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FN8755.1
May 10, 2016
ISL8205M
Pin Configuration
ISL8205M
(22 LD QFN)
TOP VIEW
PGND SYNC PG
EN
15
FS
16
SS
17
COMP
18
FB
19
13
NC
SW
11
10
9
12
m
7.5m
mm
4.5
14
VIN
1 .8 5
20
21
PGND
22
mm
SW
8
NC
7
NC
SGND
1
2
3
FB
VSENSE
PGND
4
5
VSENSE NC
6
VOUT
Pin Descriptions
PIN
NUMBER
PIN
NAME
1, 19
FB
Voltage setting pin. Module output voltage is set by connecting a resistor, RSET, from this pin to SGND. A ceramic
capacitor is also recommended to be placed in parallel with RSET from FB to SGND to ensure system stability in extreme
operation conditions. Refer to Table 2 on page 14 for the resistor and capacitor values for various typical output voltage.
2, 4
VSENSE
Voltage sense pin. Pins 2 and 4 are shorted together internally. An internal 51Ω resistor is connected from VOUT (Pad 6)
to VSENSE for local output voltage feedback in case remote sensing is not present. To achieve best regulation
performance at point of load, remote sensing trace needs to be directly routed to VSENSE.
3, 14
PGND
Power ground. Power ground pins. Place output capacitor across VOUT and PGND close to Pin 3 since it is the return
path for output current.
5, 7, 8, 10
NC
6
VOUT
Power output. Power output of the module. Output capacitors should be placed across this pad and Pin 3 PGND and
close to the module. Apply load between this pin and PGND Pin 3. Output voltage range: 0.6V to 5V.
9, 21
SW
Switching node. These pins can be used to monitor switch node waveform to examine switching frequency. These pins
can also be used for snubber connection. To improve system efficiency, it is recommended to connect Pins 9 and 21
with wide copper shape. However, avoid connecting SW to large copper shape to minimize radiated EMI noise.
11
VIN
Power input. Input voltage range: 2.6V to 5.5V. Tie directly to the input rail. It is required to have a minimum total input
capacitance of 44µF at module input. Add additional capacitance if possible. Use X5R or X7R ceramic capacitors. It is
critical to place input ceramic capacitors as close as possible to module input. Refer to “PCB Layout
Recommendations” on page 19 for more information.
12
PG
Power-good pin. Power-good is an open-drain output. Use a 10kΩ to 100kΩ pull-up resistor connected between VIN and
PG. During power-up or EN pin start-up, PG rising edge is delayed by 1ms upon output reached within regulation.
13
SYNC
Synchronization pin. Mode selection pin. Connect to logic high or input voltage VIN for PWM mode. Connect to logic low
or ground for PFM mode. Connect to an external clock for synchronization with the positive edge trigger. There is an
internal 1MΩ pull-down resistor to prevent an undefined logic state in case SYNC pin is floating. Therefore, PFM mode
is enabled when SYNC is left floating.
15
EN
Power enable pin. Enables the output, when driven high. Shuts down the output and discharges the output capacitor
when driven low. Typically tie to VIN pin directly. Do not leave this pin floating.
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DESCRIPTION
No connection pins. These pins have no connections inside. Leave these pins floating.
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ISL8205M
Pin Descriptions (Continued)
PIN
NUMBER
PIN
NAME
16
FS
Frequency selection pin. This pin sets the module switching frequency. The default frequency is 1.8MHz if FS is
connected to VIN. In spite of default setting, a resistor, RFS, can be connected from the FS pin to SGND to adjust
switching frequency ranging from 680kHz to 3.5MHz.
17
SS
Soft-start pin. SS is used to adjust the soft-start time. Connect to SGND for internal 1ms rise time. Connect a capacitor
from SS to SGND to adjust the soft-start time. The capacitor value should be less than 33nF to ensure proper operation.
18
COMP
Compensation pin. COMP is the output of the voltage feedback error amplifier. For most applications, the internal
compensation network can be used to stabilize the system and achieve optimal transient response. This can be done
by directly connecting COMP to VIN. For other applications where external compensation is desired, COMP needs to be
disconnected from VIN and tied to the external compensation network.
Exposed
Pad 20
PGND
The exposed pad is connected internally to PGND. Solid connection should be made between Pad 20 and PGND plane
on PCB. Place as many vias as possible under the pad connecting to PGND plane(s) for optimal electrical and thermal
performance. Refer to “PCB Layout Recommendations” on page 19 for more information.
22
SGND
Signal ground pin. Connect PCB SGND plane to this pin. Internally, this pin is single-point connected to module PGND.
DESCRIPTION
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
PART
MARKING
TEMP. RANGE
(°C)
TAPE AND REEL
(UNITS)
PACKAGE
(RoHS Compliant)
PKG.
DWG. #
ISL8205MIRZ-T
ISL8205M
-40 to +85
4k
22 Ld QFN
L22.4.5x7.5
ISL8205MIRZ-T7A
ISL8205M
-40 to +85
250
22 Ld QFN
L22.4.5x7.5
ISL8205MEVAL1Z
Evaluation Board
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 ISL8205M. For more information on MSL, please see Technical Brief
TB363.
TABLE 1. KEY DIFFERENCES BETWEEN FAMILY OF PARTS
PART
NUMBER
MAX OUTPUT CURRENT IOUT
(DC)
ISL8205M
5A
ISL8203M
3A dual, 6A single
ISL8202M
3A
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FN8755.1
May 10, 2016
ISL8205M
Absolute Maximum Ratings
Thermal Information
(Reference to GND)
Thermal Resistance (Typical)
JA (°C/W) JC (°C/W)
22 Ld QFN (Notes 4, 5) . . . . . . . . . . . . . . . .
27.4
4.8
Junction Temperature Range . . . . . . . . . . . . . . . . . . . . . . .-55°C to +125°C
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see TB493
VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 5.8V (DC) or 7V (20ms)
EN, FS, PG, SYNC, VFB . . . . . . . . . . . . . . . . . . . . . . . .-0.3V (DC) to VIN +0.3V
SW . . . . . . . . . . . . . . . -1.5V (100ns)/-0.3V (DC) to 6.5V (DC) or 7V (20ms)
COMP, SS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 2.7V
ESD Ratings
Human Body Model (Tested per JS-001-2010) . . . . . . . . . . . . . . . . . . 2kV
Charged Device Model (Tested per JS-002-2014) . . . . . . . . . . . . . . 750V
Machine Model (Tested per JESD22-A115C) . . . . . . . . . . . . . . . . . . 200V
Latch-Up (Tested per JESD-78D; Class 2, Level A) . . . . . 100mA at +85°C
Recommended Operating Conditions
VIN Supply Voltage Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6V to 5.5V
VOUT Voltage Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.6V to 5V
Load Current Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0A to 5A
Ambient Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
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 the ISL8205MEVAL1Z evaluation board with “direct attach” features. Refer to
ISL8205MEVAL1Z User Guide for evaluation board details. Also see Tech Brief TB379 for general thermal metric information.
5. For JC, “case temperature” location is at the center of the exposed metal pad on the package underside.
Electrical Specifications Unless otherwise noted, typical specifications are measured at VIN = 3.6V, VOUT = 1.2V, TA = +25°C.
Boldface limits apply across the operating temperature range, -40°C to +85°C.
PARAMETER
SYMBOL
VIN Undervoltage Lockout Threshold (Note 7)
VUVLO
TEST CONDITIONS
MIN
(Note 6)
TYP
MAX
(Note 6)
UNIT
2.3
2.5
V
INPUT SUPPLY
Rising, no load
Falling, no load
Quiescent Supply Current
IVIN
Shutdown Supply Current
ISD
2.10
2.25
V
SYNC = GND, EN = high, IOUT = 0A
50
µA
SYNC = VIN, fSW = 1.6MHz, EN = high,
IOUT = 0A
18
24
mA
SYNC = GND, VIN = 5.5V, EN = low
5
20
µA
5
A
OUTPUT REGULATION
Output Continuous Current Range
IOUT(DC)
Line Regulation
ΔVOUT/VOUT VIN = 2.6V to 5.5V, VOUT = 1.2V, fSW = 1.6MHz,
IOUT = 0A, PWM mode
0.65
%
VIN = 2.6V to 5.5V, VOUT = 1.2V, fSW = 1.6MHz,
IOUT = 5A, PWM mode
0.46
%
VIN = 5V, VOUT = 1.2V, fSW = 1.6MHz,
IOUT = 0A to 5A, PWM mode
0.6
%
VIN = 5V, VOUT = 3.3V, fSW = 3MHz,
IOUT = 0A to 5A, PWM mode
0.62
%
Load Regulation
Output Voltage Accuracy (Note 8)
Over line/load/temperature range, PWM
mode, VOUT = 1.2V to 3.3V
Output Ripple Voltage
ΔVOUT
Reference Voltage (Note 7)
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VREF
6
-1.6
1.6
%
VIN = 5V, 2x22µF ceramic output capacitor,
PWM mode
IOUT = 0A, VOUT = 1.2V, fSW = 1.6MHz
11
mVP-P
IOUT = 5A, VOUT = 1.2V, fSW = 1.6MHz
12
mVP-P
IOUT = 0A, VOUT = 3.3V, fSW = 3MHz
8
mVP-P
IOUT = 5A, VOUT = 3.3V, fSW = 3MHz
10
mVP-P
0.594
0.600
0.606
V
FN8755.1
May 10, 2016
ISL8205M
Electrical Specifications Unless otherwise noted, typical specifications are measured at VIN = 3.6V, VOUT = 1.2V, TA = +25°C.
Boldface limits apply across the operating temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
VFB Bias Current (Note 7)
IFB
Soft-Start Ramp Time Cycle (Note 7)
Soft-Start Charging Current (Note 7)
TEST CONDITIONS
MIN
(Note 6)
VFB = 0.75V
SS = GND
ISS
VSS = 0.1V
1.45
TYP
MAX
(Note 6)
UNIT
0.1
µA
1
ms
1.85
2.25
µA
DYNAMIC CHARACTERISTICS
Voltage Change for Positive Load Step
ΔVOUT-DP
Current slew rate = 1A/µs, VIN = 5V, 2 x 22µF
ceramic output capacitor
VOUT = 1.2V, IOUT = 0A to 5A, fSW = 1.6MHz
120
mVP-P
69
mVP-P
VOUT = 1.2V, IOUT = 5A to 0A, fSW = 1.6MHz
127
mVP-P
VOUT = 3.3V, IOUT = 5A to 0A, fSW = 3MHz
79
mVP-P
VOUT = 3.3V, IOUT = 0A to 5A, fSW = 3MHz
Voltage Change for Negative Load Step
ΔVOUT-DP
Current slew rate = 1A/µs, VIN = 5V, 2 x 22µF
ceramic output capacitor
OVERCURRENT PROTECTION (Note 7)
Current Limit Blanking Time
tOCON
17
Clock pulses
Overcurrent and Auto Restart Period
tOCOFF
8
SS cycle
Positive Peak Overcurrent Limit
IPLIMIT
7.5
9
11
A
ISKIP
1
1.3
1.8
A
300
mA
Positive Skip Limit
Zero Cross Threshold
-300
Negative Current Limit
INLIMIT
-4.5
-3
-1.5
A
Rt
0.119
0.140
0.166
Ω
COMPENSATION (Note 7)
Current Sensing Gain
Error Amplifier Transconductance
Internal compensation
60
µA/V
External compensation
120
µA/V
VIN = 5V, IO = 200mA
36
63
mΩ
VIN = 2.7V, IO = 200mA
52
89
mΩ
VIN = 5V, IO = 200mA
13
30
mΩ
VIN = 2.7V, IO = 200mA
17
36
mΩ
SWITCH NODE (Note 7)
P-Channel MOSFET ON-Resistance
N-Channel MOSFET ON-Resistance
SW Maximum Duty Cycle
100
SW Minimum On-Time
SYNC = High
%
115
ns
2070
kHz
OSCILLATOR
Nominal Switching Frequency
fSW
SYNC = VIN
1835
fSW with RFS = 261kΩ
800
kHz
fSW with RFS = 124kΩ
1600
kHz
SYNC Logic LOW to HIGH Transition Range
0.70
SYNC Hysteresis
0.75
0.80
0.15
SYNC Logic Input Leakage Current
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1600
7
VIN = 3.6V
3.6
V
V
5
µA
FN8755.1
May 10, 2016
ISL8205M
Electrical Specifications Unless otherwise noted, typical specifications are measured at VIN = 3.6V, VOUT = 1.2V, TA = +25°C.
Boldface limits apply across the operating temperature range, -40°C to +85°C. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
(Note 6)
TYP
MAX
(Note 6)
UNIT
0.3
V
0.10
µA
PG (Note 7)
Output Low Voltage
PG Pin Leakage Current
PG = VIN
0.01
OVP PG Rising Threshold
0.80
UVP PG Rising Threshold
80
UVP PG Hysteresis
85
V
90
30
PGOOD Delay Time (Rising Edge)
Time from VOUT reaching regulation
0.5
PGOOD Delay Time (Falling Edge)
1
%
mV
2
7.5
ms
µs
EN (Note 7)
Logic Input Low
0.4
Logic Input High
0.9
V
V
Enable Logic Input Leakage Current
Pulled up to 3.6V
0.1
1
µA
Thermal Shutdown
Temperature Rising
150
°C
Thermal Shutdown Hysteresis
Temperature Falling
25
°C
NOTES:
6. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design.
7. Parameters with MIN and/or MAX limits are 100% tested for internal IC prior to module assembly, unless otherwise specified. Temperature limits
established by characterization and are not production tested.
8. A 0.1% tolerance resistor is used for RSET.
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May 10, 2016
ISL8205M
Typical Performance Characteristics
Efficiency
TA = +25°C.
100.0
100.0
95.0
95.0
EFFICIENCY (%)
EFFICIENCY (%)
90.0
85.0
80.0
75.0
Vout=1V, Fsw=1.3MHz
Vout=1.2V, Fsw=1.6MHz
Vout=1.8V, Fsw=2MHz
Vout=2.5V, Fsw=2.5MHz
70.0
65.0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
85.0
80.0
Vout=1V, Fsw=1.3MHz
Vout=1.2V, Fsw=1.6MHz
Vout=1.8V, Fsw=2MHz
Vout=2.5V, Fsw=2.5MHz
Vout=3.3V, Fsw=3MHz
75.0
70.0
65.0
60.0
60.0
0
90.0
0
5
0.5
1
1.5
100.0
100.0
95.0
95.0
90.0
90.0
85.0
80.0
Vout=1V, Fsw=1.3MHz
Vout=1.2V, Fsw=1.6MHz
70.0
Vout=1.8V, Fsw=2MHz
65.0
2.5
3
3.5
4
4.5
5
FIGURE 5. EFFICIENCY TA = +25°C, VIN = 5V PFM MODE
EFFICIENCY (%)
EFFICIENCY (%)
FIGURE 4. EFFICIENCY TA = +25°C, VIN = 3.3V PFM MODE
75.0
2
LOAD CURRENT (A)
LOAD CURRENT (A)
85.0
80.0
Vout=1V, Fsw=1.3MHz
Vout=1.2V, Fsw=1.6MHz
Vout=1.8V, Fsw=2MHz
Vout=2.5V, Fsw=2.5MHz
Vout=3.3V, Fsw=3MHz
75.0
70.0
65.0
Vout=2.5V, Fsw=2.5MHz
60.0
60.0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
LOAD CURRENT (A)
FIGURE 6. EFFICIENCY TA = +25°C, VIN = 3.3V PWM MODE
Output Voltage Ripple
1µs/DIV
FIGURE 8. VIN = 5V, VOUT = 3.3V, IOUT = 0A, fSW = 3MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
9
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
LOAD CURRENT (A)
FIGURE 7. EFFICIENCY TA = +25°C, VIN = 5V PWM MODE
TA = +25°C.
20mV/DIV
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5
20mV/DIV
1µs/DIV
FIGURE 9. VIN = 5V, VOUT = 3.3V, IOUT = 5A, fSW = 3MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
FN8755.1
May 10, 2016
ISL8205M
Typical Performance Characteristics
(Continued)
20mV/DIV
20mV/DIV
1µs/DIV
1µs/DIV
FIGURE 10. VIN = 5V, VOUT = 1.2V, IOUT = 0A, fSW = 1.6MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
FIGURE 11. VIN = 5V, VOUT = 1.2V, IOUT = 5A, fSW = 1.6MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
20mV/DIV
20mV/DIV
1µs/DIV
1µs/DIV
FIGURE 12. VIN = 3.3V, VOUT = 2.5V, IOUT = 0A, fSW = 2.5MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
Load Transient Response
TA = +25°C, load current step slew rate: 1A/µs.
IOUT 2A/DIV
IOUT 2A/DIV
VOUT 50mV/DIV
VOUT 50mV/DIV
100µs/DIV
100µs/DIV
FIGURE 14. VIN = 5V, VOUT = 1V, IOUT = 0 TO 5A, fSW = 1.3MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
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FIGURE 13. VIN = 3.3V, VOUT = 2.5V, IOUT = 5A, fSW = 2.5MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
10
FIGURE 15. VIN = 5V, VOUT = 1.2V, IOUT = 0 TO 5A, fSW = 1.6MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
FN8755.1
May 10, 2016
ISL8205M
Typical Performance Characteristics
(Continued)
IOUT 2A/DIV
IOUT 2A/DIV
VOUT 50mV/DIV
VOUT 50mV/DIV
100µs/DIV
100µs/DIV
FIGURE 16. VIN = 5V, VOUT = 2.5V, IOUT = 0 TO 5A, fSW = 2.5MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
Start-Up
FIGURE 17. VIN = 5V, VOUT = 3.3V, IOUT = 0 TO 5A, fSW = 3MHz,
COUT = 2 x 22µF CERAMIC CAPACITORS
TA = +25°C, Resistor load is used in the test.
SW 5V/DIV
SW 5V/DIV
VOUT 500mV/DIV
VOUT 500mV/DIV
IOUT 2A/DIV
PGOOD 5V/DIV
PGOOD 5V/DIV
IOUT 1A/DIV
500µs/DIV
500µs/DIV
FIGURE 18. SOFT-START WITH 0A LOAD PWM MODE, VIN = 5V,
VOUT = 1.2V, IOUT = 0A, COUT = 2 x 22µF CERAMIC
CAPACITORS, CIN = 100µF POSCAP + 2 x 22µF
CERAMIC CAPACITORS
FIGURE 19. SOFT-START WITH 5A LOAD PWM MODE, VIN = 5V,
VOUT = 1.2V, IOUT = 5A, COUT = 2 x 22µF CERAMIC
CAPACITORS, CIN = 100µF POSCAP + 2 x 22µF
CERAMIC CAPACITORS
SW 5V/DIV
SW 5V/DIV
VOUT 500mV/DIV
VOUT 500mV/DIV
PGOOD 5V/DIV
IOUT 2A/DIV
PGOOD 5V/DIV
IOUT 2A/DIV
500µs/DIV
FIGURE 20. SOFT-START WITH 0A LOAD PFM MODE, VIN = 5V,
VOUT = 1.2V, IOUT = 0A, COUT = 2 x 22µF CERAMIC
CAPACITORS, CIN = 100µF POScap + 2 x 22µF
CERAMIC CAPACITORS
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11
500µs/DIV
FIGURE 21. SOFT-START WITH 5A LOAD PFM MODE, VIN = 5V,
VOUT = 1.2V, IOUT = 5A, COUT = 2 x 22µF CERAMIC
CAPACITORS, CIN = 100µF POSCAP + 2 x 22µF
CERAMIC CAPACITORS
FN8755.1
May 10, 2016
ISL8205M
Typical Performance Characteristics
(Continued)
SW 5V/DIV
SW 5V/DIV
VOUT 500mV/DIV
VOUT 500mV/DIV
PGOOD 5V/DIV
PGOOD 5V/DIV
IOUT 2A/DIV
IOUT 2A/DIV
500µs/DIV
500µs/DIV
FIGURE 23. PREBIAS SOFT-START WITH 0A LOAD PFM MODE,
VIN = 5V, VOUT = 1.2V, IOUT = 0A, COUT = 2 x 22µF
CERAMIC CAPACITORS, CIN = 100µF POSCAP +
2 x 22µF CERAMIC CAPACITORS
FIGURE 22. PREBIAS SOFT-START WITH 0A LOAD PWM MODE,
VIN = 5V, VOUT = 1.2V, IOUT = 0A, COUT = 2 x 22µF
CERAMIC CAPACITORS, CIN = 100µF POSCAP +
2 x 22µF CERAMIC CAPACITORS
Short-Circuit Protection TA = +25°C, VIN = 5V, VOUT = 1.2V, CIN = 100µF POScap + 22µF ceramic capacitors, COUT = 2 x 22µF ceramic
capacitors, output short-circuit during normal operation.
SW 2V/DIV
SW 2V/DIV
VOUT 500mV/DIV
VOUT 500mV/DIV
IIN 2A/DIV
IIN 2A/DIV
PGOOD 2V/DIV
PGOOD 2V/DIV
10µs/DIV
3.2ms/DIV
FIGURE 24. OUTPUT SHORT-CIRCUIT PROTECTION
FIGURE 25. OUTPUT SHORT-CIRCUIT PROTECTION, HICCUP MODE
SW 2V/DIV
VOUT 500mV/DIV
IIN 2A/DIV
PGOOD 2V/DIV
3.2ms/DIV
FIGURE 26. OUTPUT SHORT-CIRCUIT RECOVER FROM HICCUP
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ISL8205M
Typical Performance Characteristics
Overvoltage Protection
(Continued)
TA = +25°C, VIN = 5V, VOUT = 1.2V, CIN = 100µF POScap + 22µF ceramic capacitors, COUT = 2 x 22µF ceramic
capacitors.
SW 2V/DIV
VOUT 500mV/DIV
PGOOD 5V/DIV
500µs/DIV
FIGURE 27. OUTPUT OVERVOLTAGE PROTECTION
Power Loss
TA = +25°C, CIN = 100µF POScap + 22µF ceramic capacitors, COUT = 2 x 22µF ceramic capacitors.
2.0
Vout=1.2V, Fsw=1.6MHz PWM
1.8
Vout=3.3V, Fsw=3MHz PWM
2.2
1.6
POWER LOSS (W)
POWER LOSS (W)
2.2
1.4
1.2
1.0
0.8
0.6
2.0
Vout=1.2V, Fsw=1.6MHz PWM
1.8
Vout=2.5V, Fsw=2.5MHz PWM
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.4
0.2
0.2
0.0
0.0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0
0.5
1
1.5
LOAD CURRENT (A)
FIGURE 28. POWER LOSS AT VIN = 5V, TA = +25°C
2.5
3
3.5
4
4.5
5
FIGURE 29. POWER LOSS AT VIN = 3.3V, TA = +25°C
All of the following curves were plotted at TJ = +120°C.
6.0
6.0
5.0
5.0
LOAD CURRENT (A)
LOAD CURRENT (A)
Derating
2
LOAD CURRENT (A)
4.0
3.0
2.0
200 LFM
1.0
4.0
3.0
2.0
200 LFM
1.0
0 LFM
0 LFM
0.0
0.0
0
10
20
30
40
50
60
70
80
90 100 110 120
AMBIENT TEMPERATURE (°C)
FIGURE 30. DERATING CURVES AT VIN = 5V, VOUT = 1.2V
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13
0
10
20
30
40
50
60
70
80
90 100 110 120
AMBIENT TEMPERATURE (°C)
FIGURE 31. DERATING CURVES AT VIN = 5V, VOUT = 3.3V
FN8755.1
May 10, 2016
ISL8205M
(Continued)
6.0
6.0
5.0
5.0
LOAD CURRENT (A)
LOAD CURRENT (A)
Typical Performance Characteristics
4.0
3.0
2.0
200 LFM
1.0
4.0
3.0
2.0
200 LFM
1.0
0 LFM
0 LFM
0.0
0.0
0
10
20
30
40
50
60
70
80
90 100 110 120
0
10
20
30
40
50
60
70
80
90 100 110 120
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
FIGURE 32. DERATING CURVES AT VIN = 3.3V, VOUT = 1.2V
FIGURE 33. DERATING CURVES AT VIN = 3.3V, VOUT = 2.5V
TABLE 2. ISL8205M DESIGN GUIDE MATRIX (REFER TO Figure 1)
VIN (V)
VOUT (V)
fSW (MHz)
CIN (µF)
COUT (µF)
RFS (kΩ)
RSET (kΩ)
CFF (pF)
5
0.6
0.8
2x22
1x100
261
OPEN
390
5
0.9
1.2
2x22
3x22
169
200
560
5
1
1.3
2x22
3x22
154
150
560
5
1.2
1.6
2x22
2x22
124
100
820
5
1.5
1.7
2x22
2x22
115
66.5
560
5
1.8
2
2x22
2x22
95.3
49.9
470
5
2.5
2.5
2x22
2x22
75
31.6
330
5
3.3
3
2x22
2x22
59
22.1
330
3.3
0.6
0.8
2x22
1x100
261
OPEN
390
3.3
0.9
1.2
2x22
3x22
169
200
560
3.3
1
1.3
2x22
3x22
154
150
560
3.3
1.2
1.6
2x22
2x22
124
100
820
3.3
1.5
1.7
2x22
2x22
115
66.5
560
3.3
1.8
2
2x22
2x22
95.3
49.9
470
3.3
2.5
2.5
2x22
2x22
75
31.6
330
PWM
PFM
PWM
CLOCK
16 CYCLES
PFM CURRENT LIMIT
IL
LOAD CURRENT
0
NOMINAL +1.2%
VOUT
NOMINAL
NOMINAL -2.5%
FIGURE 34. PFM MODE OPERATION WAVEFORMS
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May 10, 2016
ISL8205M
Functional Description
The ISL8205M is a single channel 5A step-down high efficiency
power module optimized for FPGA, DSP and Li-ion battery power
devices. The module switches at 1.8MHz by default when the FS
pin is shorted to VIN. The switching frequency is also adjustable
from 680kHz to 3.5MHz through a resistor, RFS, from FS to
SGND. To boost light-load efficiency, ISL8205M can also be
configured to operate in PFM mode by pulling the SYNC pin to
SGND. Peak current mode control scheme is implemented for
fast transient response. By shorting the COMP pin to VIN, the
module utilizes internal compensation to stabilize system and
optimize transient response. Other excellent features include
external synchronization, 100% duty cycle operation and very low
quiescent current.
PWM Control Scheme
Pulling the SYNC pin high (>0.8V) forces the module into PWM
mode, regardless of output current. The ISL8205M employs the
current-mode Pulse-Width Modulation (PWM) control scheme for
fast transient response and pulse-by-pulse current limiting. As
shown in Figure 3 on page 3, the current loop consists of the
oscillator, the PWM comparator, current sensing circuit and the
slope compensation for the current loop stability. The slope
compensation is 440mV/Ts, which changes with frequency. The
gain for the current sensing circuit is typically 140mV/A. The
control reference for the current loops comes from the Error
Amplifier's (EAMP) output.
The PWM operation is initialized by the clock from the oscillator.
The P-channel MOSFET is turned on at the beginning of a PWM
cycle and the current in the MOSFET starts to ramp-up. When the
sum of the current amplifier, CSA and the slope compensation
reaches the control reference of the current loop, the PWM
comparator COMP sends a signal to the PWM logic to turn off the
PFET and turn on the N-channel MOSFET. The NFET stays on until
the end of the PWM cycle. Figure 35 shows the typical operating
waveforms during the PWM operation. The dotted lines illustrate
the sum of the slope compensation ramp and the Current-Sense
Amplifier’s (CSA) output.
start-up and will be discussed separately, please refer to “Soft
Start-Up” on page 16. The error amplifier is a transconductance
amplifier that converts the voltage error signal to a current
output. When the COMP is tied to VIN, the voltage loop is
internally compensated with the 55pF and 100kΩ RC network.
PFM (SKIP) Mode
Pulling the SYNC pin LOW (
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