Data Sheet No. PD60293
IRS254(0,1)(S)PbF
LED BUCK REGULATOR CONTROL IC
Description
The IRS254(0,1) are high voltage, high frequency
buck control ICs for constant LED current regulation.
They incorporate a continuous mode time-delayed
hysteretic buck regulator to directly control the
average load current, using an accurate on-chip
bandgap voltage reference.
The application is inherently protected against short
circuit conditions, with the ability to easily add open-
circuit protection. An external high-side bootstrap
circuit drives the buck switching element at high
frequencies. A low-side driver is also provided for
synchronous rectifier designs. All functions are
realized within a simple 8 pin DIP or SOIC package.
Features
•
200 V (IRS2540) and 600 V (IRS2541) half bridge
driver
•
Micropower startup (<500
µA)
•
±2% voltage reference
•
140 ns deadtime
•
15.6 V zener clamp on V
CC
•
Frequency up to 500 kHz
•
Auto restart, non-latched shutdown
•
PWM dimmable
•
Small 8-Lead DIP/8-Lead SOIC packages
Packages
8-Lead PDIP
IRS254(0,1)PbF
8-LeadSOIC
IRS254(0,1)SPbF
Typical Application Diagram
VBUS
L2
VOUT
+
RS1
RS2
DBOOT
IC1
CVCC1
ROV1
CBUS2
CBUS1
DOV
ROV2
CEN
ENN
VCC
COM
1
2
8
7
6
5
VB
IRS254(0,1)
HO
RG1
CBOOT
DCLAMP
CVCC2
M1
L1
IFB
3
4
VS
LO
M2
RG2
COUT
VOUT
-
RF
RCS
ROUT
CF
COM
EN
DEN1
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IRS254(0,1)(S)PbF
Alternate application circuit using a single MOSFET
IRS254(0,1)
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IRS254(0,1)(S)PbF
Absolute Maximum Ratings
Absolute maximum ratings indicate sustained limits beyond which damage to the device may occur. All voltage
parameters are absolute voltages referenced to COM, all currents are defined positive into any lead. The thermal
resistance and power dissipation ratings are measured under board mounted and still air conditions.
Symbol
V
B
V
S
V
HO
V
LO
V
IFB
V
ENN
I
CC
dV/dt
P
D
R
THJA
T
J
T
S
T
L
Definition
High-side floating supply voltage
High-side floating supply offset voltage
High-side floating output voltage
Low-side output voltage
Feedback voltage
Enable voltage
Supply current (Note 1)
Allowable offset voltage slew rate
Package power dissipation @ T
A
≤
+25 ºC
P
D
= (T
JMAX
-T
A
)/R
THJA
Thermal resistance, junction to ambient
Junction temperature
Storage temperature
Lead temperature (soldering, 10 seconds)
(8-Pin DIP)
(8-Pin SOIC)
(8-Pin DIP)
(8-Pin SOIC)
IRS2540
IRS2541
Min.
-0.3
-0.3
V
B
– 25
V
S
– 0.3
-0.3
-0.3
-0.3
-20
-50
---
---
---
---
-55
-55
---
Max.
225
625
V
B
+ 0.3
V
B
+ 0.3
V
CC
+ 0.3
V
CC
+ 0.3
V
CC
+ 0.3
20
50
1
0.625
125
200
150
150
300
Units
V
mA
V/ns
W
ºC/W
ºC
Note 1: This IC contains a zener clamp structure between the chip V
CC
and COM, with a nominal breakdown voltage of
15.6 V. Please note that this supply pin should not be driven by a low impedance DC power source greater than V
CLAMP
specified in the electrical characteristics section.
Recommended Operating Conditions
For proper operation the device should be used within recommended conditions.
Symbol
V
BS
V
S
V
CC
I
CC
T
J
Definition
High side floating supply voltage
IRS2540
Steady state high-side floating supply offset voltage
Supply voltage
Supply current
Junction temperature
IRS2541
Min.
V
CC
– 0.7
-1
-1
V
CCUV+
Note 2
-25
Max.
V
CLAMP
200
600
V
CLAMP
10
125
Units
V
mA
ºC
Note 2: Sufficient current should be supplied to V
CC
to keep the internal 15.6 V zener regulating at V
CLAMP
.
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IRS254(0,1)(S)PbF
Electrical Characteristics
V
CC
= V
BS
= V
BIAS
= 14 V +/- 0.25 V, C
LO
=C
HO
=1000 pF, C
VCC
=C
VBS
=0.1 µF, T
A
=25 °C unless otherwise specified.
Symbol
Definition
V
CC
supply undervoltage positive going
threshold
V
CC
supply undervoltage negative going
threshold
V
CC
supply undervoltage lockout hysteresis
UVLO mode quiescent current
Diesabled mode quiescent current
Quiescent V
CC
supply current
V
CC
supply current, f = 50 kHz
V
CC
zener clamp voltage
Min
Typ Max
Units Test Conditions
Supply Characteristics
V
CCUV+
V
CCUV-
V
UVHYS
I
QCCUV
I
QCCENN
I
QCC
I
CC50k
V
CLAMP
8.0
6.5
1.0
---
---
---
---
14.6
9.0
7.5
1.2
50
1.0
1.0
2.0
15.6
10.0
8.5
2.0
150
2.0
2.0
3.0
16.6
V
mA
µA
V
CC
=6 V
EN>V
ENTH+
I
FB
= 1 V
Duty Cycle = 50%
f = 50 kHz
I
CC
= 10 mA
V
V
CC
rising from 0 V
V
CC
falling from 14 V
Floating Supply Characteristics
I
QBS0
I
QBS1
V
BSUV+
V
BSUV-
I
LK
Quiescent V
BS
supply current
Quiescent V
BS
supply current
V
BS
supply undervoltage positive going
threshold
V
BS
supply undervoltage negative going
threshold
Offset supply leakage current
---
---
6.5
6.0
---
1.0
2.0
7.5
7.0
1
2.0
3.0
8.5
V
8.0
50
µA
IRS2540:V
B
=V
S
=200 V
IRS2541:V
B
=V
S
=600 V
mA
V
HO
= V
S
I
FB
= 0 V
Current Control Operation
V
ENNTH+
V
ENNTH-
V
0.5
V
IFBTH
f
ENN pin positive threshold
ENN pin negative threshold
0.5 V voltage reference (die level test)
IFB pin threshold
Maximum frequency
2.5
1.7
490
455
---
2.7
2.0
500
500
500
3.0
2.3
510
540
---
kHz
V
mV
Gate Driver Output Characteristics
V
OL
V
HL
t
r
t
f
I
O+/-
DT
t
LO,ON
t
LO,OFF
t
HO,ON
t
HO,OFF
Low level output voltage (HO or LO)
High level output voltage (HO or LO)
Turn-on rise time
Turn-off fall time
Output source/sink short circuit pulsed current
Deadtime
Delay between V
IFB
>V
IFBTH
and LO turn-on
Delay between V
IFB
<V
IFBTH
and LO turn-off
Delay between V
IFB
<V
IFBTH
and HO turn-on
Delay between V
IFB
>V
IFBTH
and HO turn-off
---
---
---
---
---
---
---
---
---
---
COM
V
CC
50
30
0.5/0.7
140
320
180
320
180
---
---
120
50
---
---
---
---
---
---
ns
I
FB
= 50 kHz square
wave, 200 mV pk-pk
DC offset = 400 mV
Duty Cycle = 50%
A
ns
V
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Page 4
IRS254(0,1)(S)PbF
Electrical Characteristics
V
CC
= V
BS
= V
BIAS
= 14 V +/- 0.25 V, C
LO
=C
HO
=1000 pF, C
VCC
=C
VBS
=0.1 µF, T
A
=25 °C unless otherwise specified.
Symbol
Watchdog timer
t
WD
P
WWD
Definition
Watchdog timer period
LO pulse width
Min
---
---
Typ Max
20
1.0
---
---
Units Test Conditions
µs
I
FB
=1 V
Functional Block Diagram
8
DELAY
LEVEL
SHIFT
PULSE
FILTER &
LATCH
VB
HO
VS
7
6
IFB
3
1
UVLO
UVN
DELAY
15.6 V
VCC
LO
5
ENN
4
100 K
2V
BANDGAP
REFERENCE 0. 5 V
Watchdog
Timer20
µS
1
µS
Pulse
Generator
2
COM
Values in block diagram are typical values
Lead Assignment
Pin Assignments
VCC 1
8
VB
Pin # Symbol
1
2
3
4
5
6
7
8
VCC
COM
IFB
ENN
LO
VS
HO
VB
Description
Supply voltage
IC power & signal ground
Current feedback
Disable outputs (LO=High, HO=Low)
Low-side gate driver output
High-side floating return
High-side gate driver output
High-side gate driver floating supply
IRS254(0,1)
COM
IFB
ENN
2
3
4
7 HO
6
5
VS
LO
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