NCP4304A, NCP4304B
Secondary Side
Synchronous Rectification
Driver for High Efficiency
SMPS Topologies
The NCP4304A/B is a full featured controller and driver tailored to
control synchronous rectification circuitry in switch mode power
supplies. Due to its versatility, it can be used in various topologies such
as flyback, forward and Half Bridge Resonant LLC.
The combination of externally adjustable minimum on and off times
helps to fight the ringing induced by the PCB layout and other
parasitic elements. Therefore, a reliable and noise less operation of the
SR system is insured.
The extremely low turn off delay time, high sink current capability
of the driver and automatic package parasitic inductance
compensation system allow to maximize synchronous rectification
MOSFET conduction time that enables further increase of SMPS
efficiency.
Finally, a wide operating V
CC
range combined with two versions of
driver voltage clamp eases implementation of the SR system in 24 V
output applications.
Features
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MARKING
DIAGRAM
8
8
1
SOIC−8
D SUFFIX
CASE 751
1
4304x
ALYW
G
G
DFN8
CASE 488AF
1
4304x
NCP
4304x
ALYWG
G
•
Self-Contained Control of Synchronous Rectifier in CCM, DCM, and
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
QR Flyback Applications
Precise True Secondary Zero Current Detection with Adjustable
Threshold
Automatic Parasitic Inductance Compensation Input
Typically 40 ns Turn off Delay from Current Sense Input to Driver
Zero Current Detection Pin Capability up to 200 V
Optional Ultrafast Trigger Interface for Further Improved
Performance in Applications that Work in Deep CCM
Disable Input to Enter Standby or Low Consumption Mode
Adjustable Minimum On Time Independent of V
CC
Level
Adjustable Minimum Off Time Independent of V
CC
Level
5 A/2.5 A Peak Current Sink/Source Drive Capability
Operating Voltage Range up to 30 V
Gate Drive Clamp of Either 12 V (NCP4304A) or 6 V (NCP4304B)
Low Startup and Standby Current Consumption
Maximum Frequency of Operation up to 500 kHz
SOIC−8 Package
These are Pb-Free Devices
Notebook Adapters
High Power Density AC/DC Power Supplies
Gaming Consoles
All SMPS with High Efficiency Requirements
= Specific Device Code
x = A or B
A
= Assembly Location
L
= Wafer Lot
Y
= Year
W
= Work Week
G
= Pb−Free Package
(*Note: Microdot may be in either location)
PINOUT INFORMATION
V
CC
Min_Toff
Min_Ton
Trig/Disable
1
2
3
4
8
7
6
5
DRV
GND
COMP
CS
(NOTE: For DFN the exposed pad must be either
unconnected or preferably connected to ground.
The GND pin must be always connected to ground.)
ORDERING INFORMATION
Device
NCP4304ADR2G
NCP4304BDR2G
NCP4304AMNTWG
NCP4304BMNTWG
Package
SOIC−8
(Pb−Free)
SOIC−8
(Pb−Free)
DFN8
(Pb−Free)
DFN8
(Pb−Free)
Shipping
†
2500 /
Tape & Reel
2500 /
Tape & Reel
4000 /
Tape & Reel
4000 /
Tape & Reel
Typical Applications
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
©
Semiconductor Components Industries, LLC, 2012
September, 2012
−
Rev. 0
1
Publication Order Number:
NCP4304/D
NCP4304A, NCP4304B
Figure 1. Typical Application Example – LLC Converter
+
Vbulk
C1
R1
C2
D3
TR1
+Vout
C5
Vcc
+
FLYBACK
CONTROL
CIRCUITRY
FB
CS
DRV
D4
C3
M2
GND
C4
M1
R3
R4
R5
OK1
D5
R2
R6
Figure 2. Typical Application Example
−
DCM or QR Flyback Converter
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2
+
NCP4304A, NCP4304B
PIN FUNCTION DESCRIPTION
Pin No.
1
2
3
4
5
Pin Name
V
CC
Min_toff
Min_ton
TRIG/Disable
CS
Function
Supplies the driver
Minimum off time adjust
Minimum on time adjust
Forced reset input
Current sense of the SR
MOSFET
Compensation inductance
connection
IC ground
Pin Description
V
CC
supply terminal of the controller. Accepts up to 30 V continuously.
Adjust the minimum off time period by connecting resistor to ground.
Adjust the minimum on time period by connecting resistor to ground.
This ultrafast input turns off the SR MOSFET in CCM applications. Activates
sleep mode if pulled up for more than 100
ms.
This pin detects if the current flows through the SR MOSFET and/or its body
diode. Basic turn off detection threshold is 0 mV. A resistor in series with this
pin can modify the turn off threshold if needed.
Use as a Kelvin connection to auxiliary compensation inductance. If SR
MOSFET package parasitic inductance compensation is not used (like for
SMT MOSFETs), connect this pin directly to GND pin.
Ground connection for the SR MOSFET driver and V
CC
decoupling capacitor.
Ground connection for minimum ton, toff adjust resistors and trigger input.
GND pin should be wired directly to the SR MOSFET source terminal/solder-
ing point using Kelvin connection.
Driver output for the SR MOSFET.
6
COMP
7
GND
8
DRV
Gate driver output
V
DD
Min_T
OFF
Enable SET
MINIMUM OFF
TIME
GENERATOR
V
DD
100
mA
Generator Min T
OFF
START
Blanking of CS
during
Min T
OFF
, Min T
ON
CS
DETECTION CS
&
COMPENSATION
ZCD SET
ZCD Reset
&
&
DRV Set Enable
DRV Reset
&
OR
S
R
Q
Q
DRIVER
DRV Out
DRV
COMP
1k5
Enable RESET
V
DD
Min_T
ON
MINIMUM ON
TIME
GENERATOR
V
DD
INV
V
CC
MANAGEMENT
UVLO
V
CC
Generator Min T
ON
START
TIMER
100
ms
One shoot
S
ZCD Reset
R
Q
Q
OR
Sleep Mode
GND
Trig/Disable
10
mA
&
V
TH
= 2 V
Trigger Blanking
150 ns
during DRV rising edge
INV
INV
One shoot
150 ns
Figure 3. Internal Circuit Architecture
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3
NCP4304A, NCP4304B
MAXIMUM RATINGS
Symbol
V
CC
V
DRV
V
CS
V
Csdyn
V
TRIG
V
Min_ton
, V
Min_toff
I
_Min_Toff
, I
_Min_Toff
VGND−COMP
VGND−COMP_dyn
ICOMP
R
qJA
R
qJA
R
qJA
T
Jmax
T
Smax
T
Lmax
IC supply voltage
Driver output voltage
Current sense input dc voltage
Current sense input dynamic voltage (t
pw
= 200 ns)
Trigger input voltage
Min_Ton and Min_Toff input voltage
Min_Ton and Min_Toff current
Static voltage difference between GND and COMP pins (internally clamped)
Dynamic voltage difference between GND and COMP pins (t
pw
= 200 ns)
Current into COMP pin
Thermal Resistance Junction−to−Air, SOIC
−
A/B versions
Thermal Resistance Junction−to−Air, DFN
−
A/B versions, 50 mm
2
−
1.0 oz. Copper
spreader
Thermal Resistance Junction−to−Air, DFN
−
A/B versions, 600 mm
2
−
1.0 oz. Copper
spreader
Maximum junction temperature
Storage Temperature Range
Lead temperature (Soldering, 10 s)
ESD Capability, Human Body Model except pin V
CS
– pin 5, HBM ESD Capability on
pin 5 is 650 V
ESD Capability, Machine Model
Rating
Value
−0.3
to 30
−0.3
to 17
−4
to 200
−10
to 200
−0.3
to 10
−0.3
to 10
−10
to +10
−3
to 10
−10
to 10
−5
to 5
180
180
80
160
−60
to +150
300
2
200
Unit
V
V
V
V
V
V
mA
V
V
mA
°C/W
°C/W
°C/W
°C
°C
°C
kV
V
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. This device series contains ESD protection and exceeds the following tests:
Pin 1−8: Human Body Model 2000 V per JEDEC Standard JESD22−A114E.
Machine Model Method 200 V pre JEDEC Standard JESD22−A115−A
2. This device meets latchup tests defined by JEDEC Standard JESD78.
= 12 V, C
load
= 0 nF, R
_min_ton
= R
_min_toff
= 10 kW, V
trig
= 0 V, f_CS = 100 kHz, DC_CS = 50%, V
CS_high
= 4 V, V
CS_low
=
−1
V unless
otherwise noted)
Symbol
SUPPLY SECTION
V
CC_on
V
CC_off
V
CC_hyste
I
CC1_A
I
CC1_B
I
CC2_A
I
CC2_B
I
CC3_A
I
CC3_B
I
CC_StartUp
I
CC_Disable_1
I
CC_Disable_2
Turn−on threshold level (V
CC
going up)
Minimum operating voltage after turn−on (V
CC
going down)
V
CC
hysteresis
Internal IC consumption (no output load on pin 8, F
sw
= 500 kHz,
T
on_min
= 500 ns, T
off_min
= 620 ns)
Internal IC consumption (C
load
= 1 nF on pin 8, F
sw
= 400 kHz,
T
on_min
= 500 ns, T
off_min
= 620 ns)
Internal IC consumption (C
load
= 10 nF on pin 8, F
sw
= 400 kHz,
T
on_min
= 500 ns, T
off_min
= 620 ns)
Startup current consumption (V
CC
= V
CC_on
−
0.1 V, no switching at
CS pin)
Current consumption during disable mode (No switching at CS pin,
V
trig
= 5 V)
Current consumption during disable mode (CS pin is switching,
F
sw
= 500 kHz, V
CS_high
= 4 V, V
CS_low
=−1 V, V
trig
= 5 V)
1
1
1
1
1
1
1
1
1
9.3
8.3
0.6
−
−
−
−
−
−
−
−
−
9.9
8.9
1.0
4.5
4.0
9.0
6.5
57.0
35.0
35
45
200
10.5
9.5
1.4
6.6
6.2
12
9
80
65
75
90
330
V
V
V
mA
mA
mA
mA
mA
mA
Rating
Pin
Min
Typ
Max
ELECTRICAL CHARACTERISTICS
(For typical values T
J
= 25°C, for min/max values T
J
=
−40°C
to +125°C, Max T
J
= 150°C, V
CC
Unit
3. Guaranteed by design.
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4
NCP4304A, NCP4304B
= 12 V, C
load
= 0 nF, R
_min_ton
= R
_min_toff
= 10 kW, V
trig
= 0 V, f_CS = 100 kHz, DC_CS = 50%, V
CS_high
= 4 V, V
CS_low
=
−1
V unless
otherwise noted)
Symbol
DRIVE OUTPUT
t
r_A
t
r_B
t
f_A
t
f_B
R
oh
R
ol
I
DRV_pk(source)
I
DRV_pk(sink)
V
DRV(min_A)
V
DRV(min_B)
V
DRV(CLMP_A)
V
DRV(CLMP_B)
CS INPUT
T
pd_on
The total propagation delay from CS input to DRV output turn on
(Vcs goes down from 4 V to
−1
V, t
f_CS
= 5 ns, COMP pin connected
to GND)
The total propagation delay from CS input to DRV output turn off
(Vcs goes up from
−1
V to 4 V, t
r_CS
= 5 ns, COMP pin connected to
GND), (Note 3)
Current sense input current source (V
CS
= 0 V)
Current sense pin turn−on input threshold voltage
Current sense pin turn−off threshold voltage, COMP pin connected
to GND (Note 3)
Compensation inverter gain
Current Sense input leakage current, V
CS
= 200 Vdc
Minimum trigger pulse width (Note 3)
Trigger input threshold voltage (V
trig
goes up)
Propagation delay from trigger input to the DRV output (V
trig
goes up
from
0
to 5 V, t
r_trig
= 5 ns)
Light load turn off filter duration
5, 8
−
60
90
ns
Output voltage rise−time for A version (C
load
= 10 nF)
Output voltage rise−time for B version (C
load
= 10 nF)
Output voltage fall−time for A version (C
load
= 10 nF)
Output voltage fall−time for B version (C
load
= 10 nF)
Driver source resistance (Note 3)
Driver sink resistance
Output source peak current
Output sink peak current
Minimum drive output voltage for A version (V
CC
= V
CCoff
+ 200 mV)
Minimum drive output voltage for B version (V
CC
= V
CCoff
+ 200 mV)
Driver clamp voltage for A version (12 < V
CC
< 28, C
load
= 1 nF)
Driver clamp voltage for B version (12 < V
CC
< 28, C
load
= 1 nF)
8
8
8
8
8
8
8
8
8
8
8
8
−
−
−
−
−
−
−
−
8.3
4.5
10
5
120
80
50
35
1.8
1
2.5
5
−
−
12
6
−
−
−
−
7
2
−
−
−
−
14.3
8
ns
ns
ns
ns
W
W
A
A
V
V
V
V
Rating
Pin
Min
Typ
Max
ELECTRICAL CHARACTERISTICS
(For typical values T
J
= 25°C, for min/max values T
J
=
−40°C
to +125°C, Max T
J
= 150°C, V
CC
Unit
T
pd_off
5, 8
−
40
55
ns
I
shift_CS
V
th_cs_on
V
th_cs_off
G
comp
I
CS
_
Leakage
t
trig_pw_min
V
trig
t
p_trig
t
trig_light_load
5
5, 8
5, 8
5,6,8
5
4
4
4
4
4
4
4
3
2
3
2
3
2
95
−120
−1
100
−85
−
−1
105
−50
0
mA
mV
mV
−
−
30
1.5
−
70
−
−
−
−
560
0.9
0.9
−
−
−
−
−
13
100
−
120
10
130
600
1.0
1.0
4.8
4.8
1
−
2.5
30
130
10
−
−
−
690
1.1
1.1
−
−
mA
ns
V
ns
ms
us
ns
mA
ns
ns
ms
ms
ms
ms
TRIGGER/DISABLE INPUT
t
trig_light_load_rec.
IC operation recovery time when leaving light load disable mode
(V
trig
goes down from
5
to 0 V, t
f_trig
= 5 ns)
t
t_blank
I
trig
T
on_min
T
off_min
T
on_min
T
off_min
T
on_min
T
off_min
Blanking time of trigger/dis during DRV rising edge (V
CS
< V
th_cs_on
,
single pulse on trigger/dis t
trig_pw
= 50 ns)
Trigger input pull down current (V
trig
= 5 V)
Minimum T
on
period (R
T_on_min
= 0
W)
Minimum T
off
period (R
T_off_min
= 0
W)
Minimum T
on
period (R
T_on_min
= 10 kW)
Minimum T
off
period (R
T_off_min
= 10 kW)
Minimum T
on
period (R
T_on_min
= 50 kW)
Minimum T
off
period (R
T_off_min
= 50 kW)
MINIMUM T
on
AND T
off
ADJUST
3. Guaranteed by design.
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