MPS MP6903DS

MP6903
Fast Turn-off Intelligent Controller
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP6903 is a low-drop diode emulator that,
combined with an external switch, replaces
Schottky diodes in high-efficiency LLC
converters. The chip regulates the forward drop
of an external switch to about 70mV and
switches it off as soon as the voltage goes
negative. MP6903 has a light-load sleep mode
that reduces the quiescent current to < 300µA.


Works with Standard and Logic-Level FETS
Compatible with Energy Star, 1W Standby
Requirements
VDD Range from 8V to 24V
Fast Turn-Off: Total Delay of 20ns
Max 400kHz Switching Frequency
<300µA Quiescent Current in Light Load
Mode
Supports DCM, CCM and CrCM Operation
Supports High-Side and Low-Side
Rectification
Power Savings of Up to 1.5W for a Typical
Notebook Adapter
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APPLICATIONS




Industrial Power Systems
Distributed Power Systems
Battery Powered Systems
LLC Converters
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Products, Quality Assurance page.
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION
U1
MP6903
Output
R2
120k
EN
Or Left
Open
Qa
Cs
R3
10k
C2
1nF
R1
100k
R5
1k
Ls
8
1
PGND
VG
2
EN
NC
7
6
3
LL
VDD
4
VD
VSS
5
VG1
C1
2.2uF
VG1
Cin
Q1
Qb
Lm
Output
C4
VG2
GND
R6
1k
Q2
MP6903
EN
1
2
C3
VG
EN
NC
3
LL
VDD
4
VD
VSS
1nF
R4 100k
PGND
8
VG2
7
6
5
U2
MP6903 Rev. 1.04
1/31/2013
www.MonolithicPower.com
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© 2013 MPS. All Rights Reserved.
1
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
ORDERING INFORMATION
Part Number*
Package
SOIC8
MP6903DS
Top Marking
MP6903
* For Tape & Reel, add suffix –Z (e.g. MP6903DS–Z);
For RoHS Compliant Packaging, add suffix –LF (e.g. MP6903DS–LF–Z)
PACKAGE REFERENCE
TOP VIEW
PGND
1
8
VG
EN
2
7
NC
LL
3
6
VDD
VD
4
5
VSS
ABSOLUTE MAXIMUM RATINGS (1)
VDD to VSS ......................................-0.3V to +27V
PGND to VSS ................................-0.3V to +0.3V
VG to VSS ......................................... -0.3V to VDD
VD to VSS .....................................-0.7V to +180V
LL, EN to VSS ...............................-0.3V to +6.5V
Maximum Operating Frequency............. 400kHz
Continuous Power Dissipation
(TA=25°C) (2)
............................................................. 1.4W
Junction Temperature ...............................150°C
Lead Temperature (Solder).......................260°C
Storage Temperature .............. -55°C to +150°C
Recommended Operation Conditions
(3)
Thermal Resistance
(4)
θJA
θJC
SOIC8 .....................................90 ...... 45 ... °C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ(MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD(MAX)=(TJ(MAX)TA)/ θJA. Exceeding the maximum allowable power dissipation
will cause excessive die temperature, and the regulator will go
into thermal shutdown. Internal thermal shutdown circuitry
protects the device from permanent damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
VDD to VSS ............................................8V to 24V
Operating Junction Temp. (TJ).... -40°C to +125°C
MP6903 Rev. 1.04
1/31/2013
www.MonolithicPower.com
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© 2013 MPS. All Rights Reserved.
2
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
ELECTRICAL CHARACTERISTICS
VDD = 12V, -40°C ≤TJ≤ 125°C, unless otherwise noted.
Parameter
VDD Voltage Range
VDD UVLO Rising
VDD UVLO hysteresis
Operating Current
Quiescent Current
Symbol Conditions
ICC
Iq
Shutdown Current
Light-Load Mode Current
Thermal Shutdown (5)
Thermal Shutdown Hysteresis (5)
Enable UVLO Rising
Enable UVLO Hysteresis
Internal Pull-up Current on EN
Pin
CONTROL CIRCUITRY SECTION
VSS –VD Forward Voltage
CLOAD=5nF, fSW=100kHz
VSS-VD=0.5V
VDD =4V
VDD=20V, EN=0V
170
30
1.1
Vfwd
55
tDon
CLOAD = 5nF
tDon
CLOAD = 10nF
Turn-on delay
Input Bias Current on VD Pin
Minimum On-Time
Light-Load-Enter Delay
Light-Load-Enter Pulse Width
Light-Load-Enter Pulse Width
Hysteresis
Light-Load Resistor Value
Light-Load Mode Exit Pulse
Width Threshold (VDS)
Light-Load Mode Enter Pulse
Width Threshold (VGS) (5)
GATE DRIVER SECTION
VG (Low)
tLL-Delay
tLL
VD = 180V
CLOAD = 5nF
RLL=100kΩ
RLL=100kΩ
tLL-H
RLL=100kΩ
tMIN
0.4
80
1.3
Typ
6.0
1
8
2
190
350
290
180
40
1.5
0.2
Max
24
7.0
1.2
10
3
260
420
400
190
50
1.9
0.4
Units
V
V
V
mA
mA
10
15
µA
70
250
650
400
1200
0.5
0.8
120
1.75
85
380
mV
680
3
1.2
150
2.2
0.2
30
VLL-DS
-400
VLL-GS
-250
13
VDD-2.2
0
VD=VSS
VD =VSS, CLOAD=5nF, RGATE=0Ω
VD =VSS, CLOAD=10nF, RGATE=0Ω
3V <VG<10V
µA
°C
°C
V
V
ns
ns
µA
µs
µs
µs
300
kΩ
-150
mV
V
0.05
14.5
0.1
16
V
V
30
60
mV
100
tDoff
tDoff
µA
µs
1.0
ILOAD=1mA
VDD >17V
VDD <17V
Turn Off Threshold (VSS-VD) (5)
Turn Off Threshold During
Blanking Time (VSS-VD) (5)
Turn-Off Propagation Delay
Pull Down Impedance
Pull Down Current (5)
-20°C≤TJ≤125°C
-40°C≤TJ<-20°C
-20°C≤TJ≤125°C
-40°C≤TJ<-20°C
RLL
VG (High)
Turn-Off, Total Delay
Min
8
4.8
0.8
15
60
60
1
2
mV
120
120
2
ns
ns
ns
Ω
A
Notes:
5) Guaranteed by Design and Characterization. Not tested in Production.
MP6903 Rev. 1.04
1/31/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
3
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
PIN FUNCTIONS
Pin #
1
2
3
4
5
6
7
8
MP6903 Rev. 1.04
1/31/2013
Name
PGND
EN
LL
VD
VSS
VDD
NC
VG
Description
Power Ground. Return for driver switch.
Enable. Active high.
Light Load Time Set. Connect a resistor to set the light load timing.
MOSFET Drain Voltage Sense.
Ground. Also used as reference for VD.
Supply Voltage.
No Connection.
Gate Drive Output.
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© 2013 MPS. All Rights Reserved.
4
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS
VDD = 12V, unless otherwise noted.
VFWD vs. Temperature
80
70
65
-50
0
50
100
150
2.4
QUIESCENT CURRENT (mA)
TURN OFF THRESHOLD (V)
-25
-30
-35
-40
-50
Shutdown Current vs.
Temperature
0
50
100
150
100
50
100
6.5
6
5.5
5
150
-50
330
1.6
EN UVLO RISING (V)
1.7
310
290
270
MP6903 Rev. 1.04
1/31/2013
50
100
1.4
1.2
150
0
50
100
150
0
50
100
7.6
7.4
7.2
7
6.8
6.6
-50
150
EN UVLO Rising vs.
Temperature
350
0
1.6
CLOAD=5nF, fSW=100kHz
7.8
Light Load Mode Current
vs. Temperature
250
-50
1.8
Operation Current vs.
Temperature
OPERATION CURRENT (mA)
VDD UVLO RISING (V)
200
0
2
VDD UVLO Rising vs.
Temperature
7
50
-50
2.2
1
-50
150
50
100
150
CLOAD=5nF
700
600
1.5
1.4
1.3
1.2
-50
0
Turn On Delay vs.
Temperature
TURN ON DELAY (ns)
VFWD (mV)
Quiescent Current vs.
Temperature
-20
75
60
Turn off threshold vs.
Temperature
0
50
100
150
500
400
300
200
100
0
-50
0
50
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© 2013 MPS. All Rights Reserved.
100
150
5
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VDD = 12V, unless otherwise noted.
Turn On Delay vs.
Temperature
CLOAD=10nF
90
TURN OFF DELAY (ns)
TURN ON DELAY (ns)
CLOAD=5nF
CLOAD=10nF
90
80
80
1,200
1,000
800
600
400
200
0
-50
Turn Off Delay vs.
Temperature
TURN OFF DELAY (ns)
1,400
Turn Off Delay vs.
Temperature
70
60
50
40
30
20
0
50
100
150
60
50
40
30
20
10
10
0
-50
70
0
50
100
0
-50
150
Minimum On Time vs.
Temperature
1.8
0.7
1.7
0.6
1.6
100
1.5
-50
150
(ns)
0.8
(5)
1.9
TURN-OFF THRESHOLD
0.9
50
100
150
60
2
0
50
Turn-off Threshold(5)
vs. Temperature
1.0
0.5
-50
0
0
50
100
150
50
40
30
20
10
0
-50
0
50
100
150
Operation in LLC Resonant
Converter
Operation in LLC Resonant
Converter
Operation in LLC Resonant
Converter
VIN=250V, VOUT=12V, IOUT=15A
DCM
VIN=263V, VOUT=12V, IOUT=15A
CRCM
VIN=280V, VOUT=12V, IOUT=15A
CCM
VDS
20V/div
VDS
20V/div
VG
5V/div
VG
5V/div
ISR
10A/div
ISR
10A/div
MP6903 Rev. 1.04
1/31/2013
VDS
20V/div
VG
5V/div
ISR
10A/div
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© 2013 MPS. All Rights Reserved.
6
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
FUNCTIONAL BLOCK DIAGRAM
Figure 1: Functional Block Diagram
OPERATION
The MP6903 supports operation in discontinuous
current mode (DCM), continuous current mode
(CCM), and critical conduction mode (CrCM)
condition. Operating in either a DCM or CrCM
condition, the control circuitry controls the gate in
forward mode and will turn the gate off when the
MOSFET current goes low. In CCM operation,
the control circuitry turns off the gate when very
fast transients occur.
Blanking
The control circuitry contains a blanking function.
When the MOSFET turns on or off, the blanking
function ensures that the previous state extends
for some minimum time period. The turn-on
blanking time is ~0.8µs. During the turn-on
blanking period, the turn-off threshold is not
totally blanked, but changes the threshold
voltage to approximately 100mV (instead of 0mV).
This assures that the part can always turn off
even during the turn-on blanking period. (The
synchronous period is recommended to be
greater than 0.8μs in CCM in the LLC Converter
to avoid shoot-through.)
MP6903 Rev. 1.04
1/31/2013
VD Clamp
A high-voltage JFET is used at the input because
VD can go as high as 180V. To avoid excessive
currents when VG goes below -0.7V, add a small
resistor between VD and the drain of the external
MOSFET.
Under-Voltage Lockout (UVLO)
When VDD drops below the UVLO threshold, the
part goes into sleep mode and a 10kΩ resistor
pulls the VG pin low.
Enable pin
EN is internal pulled up by the regulator from VDD
with a ~15uA current source. Leave this pin open
if unused.
When use external signal to control EN, it is
highly recommended the pull down current be
larger than 15uA to make sure the EN pin can be
pulled to low.
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© 2013 MPS. All Rights Reserved.
7
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
Thermal shutdown
If the junction temperature of the chip exceeds
180°C, the VG will be pulled low and the part
stops switching. The part will resume normal
function after the junction temperature has
dropped to 150°C.
Turn-On Phase
When the synchronous MOSFET is on, current
flows through its body diode and generates a
negative VDS. This body diode voltage drop (< 500mV) is much smaller than the turn-on
threshold of the control circuitry (-70mV), which
then pulls the gate driver voltage high to turn on
the synchronous MOSFET after about 250ns
turn-on delay (shown in Figure 2).
When the turn-on delay ends, turn-on starts with
a blanking time (minimum on-time: ~0.8µs), and
the turn-off threshold changes from +30mV to
+100mV. This blanking time helps to avoid errors
around the turn-off threshold caused by turn-on
ringing of the synchronous MOSFET.
Figure 2: Turn On/Off Timing Diagram
Conducting Phase
When the synchronous MOSFET turns on, VDS
rises according to the MOSFET’s ON resistance.
When VDS rises above the turn-on threshold (70mV), the control circuitry stops pulling up the
gate driver, so the gate voltage is pulled down by
the internal pull-down resistance (10kΩ) and
leakage to increase the ON resistance of the
synchronous MOSFET, which to limit the VDS
slew rate, stabilizes VDS to around -70mV even
when the current through the MOSFET is fairly
small. This function limits the driver voltage when
the synchronous MOSFET is turned off (this
function is still active during turn-on blanking,
MP6903 Rev. 1.04
1/31/2013
which means the gate driver could still be turnedoff even with very small duty cycles of the
synchronous MOSFET).
Turn-Off Phase
When VDS triggers the turn-off threshold (30mV),
the gate voltage is pulled to low after a 20ns turnoff delay (shown in Figure 2) by the control
circuitry.
Figure 3 shows synchronous rectification
operation at heavy load. The gate driver initially
saturates due to the high current. After VDS rises
above -70mV, the gate driver voltage decreases
to adjust the VDS to around -70mV.
Figure 4 shows synchronous rectification
operation at light load. The gate driver voltage
never saturates due to the low current, but
decreases as soon as the synchronous MOSFET
turns on and adjusts the VDS.
Figure 3: Synchronous Rectification
Operation at Heavy Load
Figure 4: Synchronous Rectification
Operation at Light Load
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© 2013 MPS. All Rights Reserved.
8
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
Light-Load Latch-Off Function
The gate driver of MP6903 is latched to save the
driver loss at light-load condition to improve
efficiency. See Figure5, when the synchronous
MOSFET’s conducting period keeps lower than
light load timing (TLL) for longer than the lightload-enter delay (TLL-Delay), MP6903 enters lightload mode and latches off the gate driver. Here
the synchronous MOSFET’s conducting period is
from turn on of the gate driver to the moment
when VGS drops to below 1V (VLL_GS).
Normal Mode
MP6903 is unlatched to restart the synchronous
rectification, see Figure6.
For MP6903, the light load enter timing (TLL) is
programmable by connecting a resistor (RLL) on
LL pin, by monitoring the LL pin current (the LL
pin voltage keeps at ~2V internally), TLL is set as
following (a 1nF capacitor is recommended to
decouple the noise on this pin):
TLL  RLL (k ) 
2.2us
100k
Light Load Mode
TLL-dELAY
tLL
tLL
tLL
Secondary Side Current
Figure 5: MP6903 Enters Light Load Mode
Figure 6: MP6903 Exits Light Load Mode
During light-load mode, MP6903 monitors the
synchronous MOSFET’s body diode conducting
period by sensing the time duration of the VDS
below -250mV(VLL_DS). If it is longer than TLL+TLLH (TLL-H, light-load-enter pulse width hysteresis),
the light-load mode is finished and gate driver of
MP6903 Rev. 1.04
1/31/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
9
MP6903- FAST TURN-OFF INTELLIGENT CONTROLLER
PACKAGE INFORMATION
SOIC8
0.189(4.80)
0.197(5.00)
0.050(1.27)
0.024(0.61)
8
5
0.063(1.60)
0.150(3.80)
0.157(4.00)
PIN 1 ID
1
0.228(5.80)
0.244(6.20)
0.213(5.40)
4
TOP VIEW
RECOMMENDED LAND PATTERN
0.053(1.35)
0.069(1.75)
SEATING PLANE
0.004(0.10)
0.010(0.25)
0.013(0.33)
0.020(0.51)
0.0075(0.19)
0.0098(0.25)
SEE DETAIL "A"
0.050(1.27)
BSC
SIDE VIEW
FRONT VIEW
0.010(0.25)
x 45o
0.020(0.50)
GAUGE PLANE
0.010(0.25) BSC
0o-8o
0.016(0.41)
0.050(1.27)
DETAIL "A"
NOTE:
1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN
BRACKET IS IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSIONS OR GATE BURRS.
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSIONS.
4) LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING)
SHALL BE 0.004" INCHES MAX.
5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION AA.
6) DRAWING IS NOT TO SCALE.
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP6903 Rev. 1.04
1/31/2013
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2013 MPS. All Rights Reserved.
10