MPS MP2364DF

TM
MP2364
Dual 1.5A, 23V, 1.4MHz
Step-Down Converter
The Future of Analog IC Technology
TM
DESCRIPTION
FEATURES
The MP2364 is a dual monolithic step-down
switch mode converter with built-in internal
power MOSFETs. It achieves 1.5A continuous
output current for each output over a wide input
supply range with excellent load and line
regulation.
•
•
•
Current mode operation provides fast transient
response and eases loop stabilization.
Fault condition protection includes cycle-by-cycle
current limiting and thermal shutdown. In
shutdown mode, the regulator draws 40µA of
supply current.
The MP2364 requires a minimum number of
readily available standard external components.
EVALUATION BOARD REFERENCE
Board Number
Dimensions
EV2364DF-01A
2.2”X x 1.6”Y x 0.4”Z
•
•
•
•
•
•
•
•
•
•
•
1.5A Current for Each Output
0.18Ω Internal Power MOSFET Switches
Stable with Low ESR Output Ceramic
Capacitors
Up to 90% Efficiency
40µA Shutdown Mode
Fixed 1.4MHz Frequency
Thermal Shutdown
Cycle-by-Cycle Over Current Protection
Wide 4.75V to 23V Operating Input Range
Each Output Adjustable from 0.92V to 16V
Configurable for Single Output with Double
the Current
Programmable Under Voltage Lockout
Programmable Soft-Start
Available in TSSOP20 with Exposed Pad
and SOIC Packages
APPLICATIONS
•
•
•
•
•
Distributed Power Systems
I/O and Core supplies
DSL Modems
Set top boxes
Cable Modems
“MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic
Power Systems, Inc.
TYPICAL APPLICATION
Efficiency vs
Load Current
12V
100
3.3V @ 1.5A
2
3
10nF
2A
Schottky
4
5
6
7
8
9
OFF ON
10
SSA
ENA
NC1
COMPA
BSA
FBA
INA
SWA
SGB
MP2364
PGB
PGA
SWB
SGA
INB
FBB
NC2
COMPB
BSB
ENB
SSB
20
OFF ON
19
18
82pF
17
16
15
2A
Schottky
2.5V @ 1.5A
14
13 10nF
12
11
VOUT=3.3V
90
2.2nF
EFFICIENCY (%)
1
80
VOUT=5V
VOUT=2.5V
70
60
3.3nF
50
MP2364_TAC_S01
MP2364 Rev. 1.4
3/22/2006
0
0.5
1.0
LOAD CURRENT (A)
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1.5
MP2364_EC01
1
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
PACKAGE REFERENCE
TOP VIEW
SSA
1
20
ENA
NC1
2
19
COMPA
BSA
3
18
FBA
INA
4
17
SGB
SWA
5
16
PGB
PGA
6
15
SWB
SGA
7
14
INB
FBB
8
13
NC2
COMPB
9
12
BSB
ENB
10
11
SSB
TOP VIEW
SSA
1
16
ENA
BSA
2
15
COMPA
INA
3
14
FBA
SWA
4
13
GNDB
GNDA
5
12
SWB
FBB
6
11
INB
COMPB
7
10
BSB
ENB
8
9
SSB
MP2364_PD02_SOIC16
EXPOSED PAD
FOR TSSOP20F ONLY
MP2364_PD01-TSSOP20F
Part Number*
Package
Temperature
Part Number*
Package
Temperature
MP2364DF
TSSOP20F
–40°C to +85°C
MP2364DS
SOIC16
–40°C to +85°C
*
For Tape & Reel, add suffix –Z (eg. MP2364DF–Z)
For Lead Free, add suffix –LF (eg. MP2364DF–LF–Z)
ABSOLUTE MAXIMUM RATINGS (1)
Supply Voltage (INA, INB )................................ 25V
Switch Voltage (SWA, SWB) .............................. 26V
Bootstrap Voltage (BSA, BSB) .................. VSW + 6V
Feedback Voltage (FBA, FBB) ............–0.3V to +6V
Enable/UVLO Voltage (ENA, ENB)......–0.3V to +6V
Comp Voltage (COMPA, COMPB)...........–0.3V to +6V
Soft Start Voltage (SSA, SSB).............–0.3V to +6V
Junction Temperature .............................+150°C
Lead Temperature ..................................+260°C
Storage Temperature.............. –65°C to +150°C
MP2364 Rev. 1.4
3/22/2006
*
For Tape & Reel, add suffix –Z (eg. MP2364DS–Z)
For Lead Free, add suffix –LF (eg. MP2364DS–LF–Z)
Recommended Operating Conditions
(2)
Supply Voltage (VIN) ...................... 4.75V to 23V
Operating Temperature.................–40°C to +85°C
Thermal Resistance
(3)
θJA
θJC
TSSOP20F ............................. 40 ....... 6.... °C/W
SOIC16.................................. 105 ..... 40... °C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The device is not guaranteed to function outside of its
operating conditions.
3) Measured on approximately 1” square of 1 oz copper.
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2
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
ELECTRICAL CHARACTERISTICS
VIN = 12V, TA = +25°C, unless otherwise noted.
Parameter
Symbol Condition
Feedback Voltage
VFB
Upper Switch-On Resistance RDS(ON)1
Lower Switch-On Resistance RDS(ON)2
Upper Switch Leakage
Current Limit (4)
Current Limit Gain
Output Current to Comp Pin
GCS
Voltage
Error Amplifier Voltage Gain
AVEA
Error Amplifier
GEA
Transconductance
Oscillator Frequency
fOSC
Short Circuit Frequency
fSC
Soft-Start Pin Equivalent
Output Resistance
EN Shutdown Threshold
VEN
Voltage
Enable Pull-Up Current
IEN
EN UVLO Threshold Rising
VUVLO
EN UVLO Threshold
Hysteresis
Supply Current (Shutdown)
Supply Current (Quiescent)
Thermal Shutdown
Maximum Duty Cycle
Minimum On Time
4.75V ≤ VIN ≤ 23V
Min
Typ
Max
Units
0.892
0.920
0.948
V
0.18
10
3.0
Ω
Ω
µA
A
1.95
A/V
400
V/V
VEN = 0V, VSW = 0V
10
2.5
∆IC = ±10 µA
630
VFB = 0V
930
1230
µA/V
1.4
210
MHz
KHz
9
kΩ
ICC > 100µA
0.7
1.0
1.3
V
VEN Rising
2.37
1.0
2.50
2.62
µA
V
210
IOFF
VEN ≤ 0.4V
ION
VEN ≥ 3V
DMAX
40
70
µA
2.4
2.8
mA
160
VFB = 0.8V
tON
mV
70
100
°C
%
ns
Note:
4) Equivalent output current = 1.5A ≥ 50% Duty Cycle
2.0A ≤ 50% Duty Cycle
Assumes ripple current = 30% of load current.
Slope compensation changes current limit above 40% duty cycle.
MP2364 Rev. 1.4
3/22/2006
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3
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
PIN FUNCTIONS (TSSOP20F)
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Name
Description
Soft-Start Control for Channel A. 9kΩ output resistance from the pin. Set RC time constant
with external capacitor for soft start ramp time. Ramp Time = 2.2 x 9kΩ x C.
NC
No Connect
BSA
High-Side Driver Boost Pin. Connect a 10nF capacitor from this pin to SWA.
Supply Voltage Channel A. The MP2364 operates from a +4.75V to +23V unregulated input.
INA
Input Ceramic Capacitors should be close to this pin.
SWA
Switch Channel A. This connects the inductor to either INA through M1A or to PGA through M2A.
Power Ground Channel A. This is the Power Ground Connection to the input capacitor
PGA
ground.
Signal Ground Channel A. This pin is the signal ground reference for the regulated output
voltage. For this reason care must be taken in its layout. This node should be placed outside
SGA
of the D1 to C1 ground path to prevent switching current spikes from inducing voltage noise
into the part.
Feedback Voltage for Channel B. This pin is the feedback voltage. The output voltage is ratio scaled
FBB
through a voltage divider, and the center point of the divider is connected to this pin. The voltage is
compared to the on board 0.92V reference.
Compensation Channel B. This is the output of the transconductance error amplifier. A series
COMPB RC is placed on this pin for proper control loop compensation. Please refer to more in the
datasheet.
Enable/UVLO Channel B. A voltage greater than 2.62V enables operation. Leave ENB
unconnected for automatic startup. An Under Voltage Lockout (UVLO) function can be
ENB
implemented by the addition of a resistor divider from VIN to GND. For complete low current
shutdown the ENB pin voltage needs to be less than 700mV.
Soft-Start Control for Channel B. 9kΩ output resistance from the pin. Set RC time constant
SSB
with external capacitor for soft start ramp time. Ramp Time = 2.2x9kΩxC.
BSB
High-Side Driver Boost Pin. Connect a 10nF capacitor from this pin to SWB.
NC
No Connect.
Supply Voltage Channel B. The MP2364 operates from a +4.75V to +23V unregulated input.
INB
Input Ceramic Capacitors should be close to this pin.
SWB
Switch Channel B. This connects the inductor to either INB through M1B or to PGB through M2B.
Power Ground Channel B. This is the Power Ground Connection to the input capacitor
PGB
ground.
Signal Ground Channel B. This pin is the signal ground reference for the regulated output
voltage. For this reason care must be taken in its layout. This node should be placed outside
SGB
of the D1 to C1 ground path to prevent switching current spikes from inducing voltage noise
into the part.
Feedback Voltage for Channel A. This pin is the feedback voltage. The output voltage is ratio scaled
FBA
through a voltage divider, and the center point of the divider is connected to this pin. The voltage is
compared to the on board 0.92V reference.
Compensation Channel A. This is the output of the transconductance error amplifier. A series
COMPA RC is placed on this pin for proper control loop compensation. Please refer to more in the
datasheet.
Enable/UVLO Channel A. A voltage greater than 2.62V enables operation. Leave ENA
unconnected for automatic startup. An Under Voltage Lockout (UVLO) function can be
ENA
implemented by the addition of a resistor divider from VIN to GND. For complete low current
shutdown the ENA pin voltage needs to be less than 700mV.
SSA
MP2364 Rev. 1.4
3/22/2006
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TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
PIN FUNCTIONS (SOIC16)
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Name
Description
Soft-Start Control for Channel A. 9kΩ output resistance from the pin. Set RC time constant
with external capacitor for soft start ramp time. Ramp Time = 2.2 x 9kΩ x C.
BSA
High-Side Driver Boost Pin. Connect a 10nF capacitor from this pin to SWA.
Supply Voltage Channel A. The MP2364 operates from a +4.75V to +23V unregulated input.
INA
Input Ceramic Capacitors should be close to this pin.
SWA
Switch Channel A. This connects the inductor to either INA through M1A or to PGA through M2A.
GNDA Ground A.
Feedback Voltage for Channel B. This pin is the feedback voltage. The output voltage is ratio scaled
FBB
through a voltage divider, and the center point of the divider is connected to this pin. The voltage is
compared to the on board 0.92V reference.
Compensation Channel B. This is the output of the transconductance error amplifier. A series
COMPB RC is placed on this pin for proper control loop compensation. Please refer to more in the
datasheet.
Enable/UVLO Channel B. A voltage greater than 2.62V enables operation. Leave ENB
unconnected for automatic startup. An Under Voltage Lockout (UVLO) function can be
ENB
implemented by the addition of a resistor divider from VIN to GND. For complete low current
shutdown the ENB pin voltage needs to be less than 700mV.
Soft-Start Control for Channel B. 9kΩ output resistance from the pin. Set RC time constant
SSB
with external capacitor for soft start ramp time. Ramp Time = 2.2x9kΩxC.
BSB
High-Side Driver Boost Pin. Connect a 10nF capacitor from this pin to SWB.
Supply Voltage Channel B. The MP2364 operates from a +4.75V to +23V unregulated input.
INB
Input Ceramic Capacitors should be close to this pin.
SWB
Switch Channel B. This connects the inductor to either INB through M1B or to PGB through M2B.
GNDB Ground B.
Feedback Voltage for Channel A. This pin is the feedback voltage. The output voltage is ratio scaled
FBA
through a voltage divider, and the center point of the divider is connected to this pin. The voltage is
compared to the on board 0.92V reference.
Compensation Channel A. This is the output of the transconductance error amplifier. A series
COMPA RC is placed on this pin for proper control loop compensation. Please refer to more in the
datasheet.
Enable/UVLO Channel A. A voltage greater than 2.62V enables operation. Leave ENA
unconnected for automatic startup. An Under Voltage Lockout (UVLO) function can be
ENA
implemented by the addition of a resistor divider from VIN to GND. For complete low current
shutdown the ENA pin voltage needs to be less than 700mV.
SSA
MP2364 Rev. 1.4
3/22/2006
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5
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
OPERATION
The MP2364 is a dual channel current mode
regulator. The COMP pin voltage is proportional
to the peak inductor current. At the beginning of
a cycle, the upper transistor M1 is off, and the
lower transistor M2 is on (see Figure 1). The
COMP pin voltage is higher than the current
sense amplifier output, and the current
comparator’s output is low. The rising edge of
the 1.4MHz CLK signal sets the RS Flip-Flop.
Its output turns off M2 and turns on M1 thus
connecting the SW pin and inductor to the input
supply. The increasing inductor current is
sensed and amplified by the Current Sense
Amplifier. Ramp compensation is summed to
Current Sense Amplifier output and compared
to the Error Amplifier output by the Current
Comparator.
If the sum of the Current Sense Amplifier output
and the Slope Compensation signal does not
exceed the COMP voltage, the falling edge of
the CLK resets the Flip-Flop.
The output of the Error Amplifier integrates the
voltage difference between the feedback and
the 0.92V bandgap reference. The polarity is
such that a voltage at the FB pin lower than
0.92V increases the COMP pin voltage. Since
the COMP pin voltage is proportional to the
peak inductor current, an increase in its voltage
increases current delivered to the output. The
lower 10Ω switch ensures that the bootstrap
capacitor voltage is charged during light load
conditions. External Schottky Diode D1 carries
the inductor current when M1 is off (see Figure 1).
When the sum of the Current Sense Amplifier
output and the Slope Compensation signal
exceeds the COMP pin voltage, the RS FlipFlop is reset. The MP2364 reverts to its initial
M1 off, M2 on state.
INA/
INB
CURRENT
SENSE
AMPLIFIER
INTERNAL
REGULATORS
OSCILLATOR
210/1400KHz
+
0.7V
ENA/
ENB
CLK
5V
--
+
--
BSA/
BSB
S
Q
R
Q
SWA/
SWB
CURRENT
COMPARATOR
LOCKOUT
COMPARATOR
-2.29V/
2.50V
SLOPE
COMP
SHUTDOWN
COMPARATOR
--
+
1.8V
+
--
+
FREQUENCY
FOLDBACK
COMPARATOR
--
COMPA/
COMPB
0.4V
+
ERROR
AMPLIFIER
PGA/
PGB
0.92V
SGA/
SGB
SSA/
SSB
FBA / FBB
MP2364_BD02
Figure 1—Functional Block Diagram
(Diagram portrays ½ of the MP2364)
MP2364 Rev. 1.4
3/22/2006
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TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
APPLICATION INFORMATION
COMPONENT SELECTION
The MP2364 has two channels: A and B. The
following formulas are used for component
selection of both channels. Refer to
components with reference “A” for channel A,
and components with reference “B” for channel
B, respectively, as indicated in Figure 3 (i.e. –
R1A for Channel A and R1B for Channel B).
Setting the Output Voltage
The output voltage is set using a resistive
voltage divider from the output voltage to FB
pin. The voltage divider divides the output
voltage down to the feedback voltage by the
ratio:
VFB = VOUT
R2
R1 + R2
Thus the output voltage is:
VOUT = 0.92 V ×
R1 + R2
R2
Where VFB is the feedback voltage and VOUT is
the output voltage
A typical value for R2 can be as high as 100kΩ,
but a typical value is 10kΩ. Using that value, R1
is determined by:
R1 = R2 × (
VOUT
− 1)
0.92V
For example, for a 3.3V output voltage, R2 is
10kΩ, and R1 is 25.9kΩ.
Inductor
The inductor is required to supply constant
current to the output load while being driven by
the switched input voltage. A larger value
inductor will result in less ripple current that will
result in lower output ripple voltage. However,
the larger value inductor will have a larger
physical size, higher series resistance, and/or
lower saturation current. A good rule for
determining the inductance to use is to allow
the peak-to-peak ripple current in the inductor
to be approximately 30% of the maximum
switch current limit. Also, make sure that the
peak inductor current is below the maximum
MP2364 Rev. 1.4
3/22/2006
switch current limit. The inductance value can
be calculated by:
L1 =
⎛
⎞
VOUT
V
× ⎜⎜1 − OUT ⎟⎟
fS × ∆IL ⎝
VIN ⎠
Where VIN is the input voltage, fS is the
switching frequency, and ∆IL is the peak-topeak inductor ripple current.
Choose an inductor that will not saturate under
the maximum inductor peak current.
The peak inductor current can be calculated by:
ILP = ILOAD +
⎛
⎞
VOUT
V
× ⎜⎜1 − OUT ⎟⎟
2 × fS × L1 ⎝
VIN ⎠
Where ILOAD is the load current.
Output Rectifier Diode
The output rectifier diode supplies the current to
the inductor when the high-side switch is off. To
reduce losses due to the diode forward voltage
and recovery times, use a Schottky diode.
Choose a diode whose maximum reverse
voltage rating is greater than the maximum
input voltage, and whose current rating is
greater than the maximum load current.
Input Capacitor
The input current to the step-down converter is
discontinuous, therefore a capacitor is required
to supply the AC current to the step-down
converter while maintaining the DC input
voltage. Use low ESR capacitors for the best
performance. Ceramic capacitors are preferred,
but tantalum or low-ESR electrolytic capacitors
may also suffice.
Since the input capacitor (C1) absorbs the input
switching current it requires an adequate ripple
current rating. The RMS current in the input
capacitor can be estimated by:
I C1 = ILOAD ×
VOUT ⎛⎜ VOUT
× 1−
VIN ⎜⎝
VIN
⎞
⎟
⎟
⎠
The worst-case condition occurs at VIN = 2VOUT,
where:
IC1 =
ILOAD
2
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TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
For simplification, choose the input capacitor
whose RMS current rating greater than half of
the maximum load current.
The input capacitor can be electrolytic, tantalum
or ceramic. When using electrolytic or tantalum
capacitors, a small, high quality ceramic
capacitor, i.e. 0.1µF, should be placed as close
to the IC as possible.
When using ceramic capacitors, make sure that
they have enough capacitance to provide
sufficient charge prevent excessive voltage
ripple at input. The input voltage ripple caused
by capacitance can be estimated by:
∆VIN =
ILOAD VOUT ⎛
V
×
× ⎜⎜1 − OUT
C1
VIN ⎝
VIN
⎞
⎟⎟
⎠
Output Capacitor
The output capacitor is required to maintain the
DC output voltage. Ceramic, tantalum, or low
ESR electrolytic capacitors are recommended.
Low ESR capacitors are preferred to keep the
output voltage ripple low. The output voltage
ripple can be estimated by:
∆VOUT =
VOUT ⎛
V
× ⎜1 − OUT
f S × L1 ⎜⎝
VIN
⎞
⎞ ⎛
1
⎟
⎟⎟ × ⎜ R ESR +
⎜
8 × f S × C2 ⎟⎠
⎠ ⎝
Where L1 is the inductor value, C2 is the output
capacitance value, and RESR is the equivalent
series resistance (ESR) value of the output
capacitor.
In the case of ceramic capacitors, the
impedance at the switching frequency is
dominated by the capacitance. The output
voltage ripple is mainly caused by the
capacitance. For simplification, the output
voltage ripple can be estimated by:
∆VOUT =
⎞
⎛
V
× ⎜⎜1 − OUT ⎟⎟
VIN ⎠
× L1 × C2 ⎝
VOUT
8 × fS
2
In the case of tantalum or electrolytic
capacitors, the ESR dominates the impedance
at the switching frequency. For simplification,
the output ripple can be approximated to:
∆VOUT =
VOUT ⎛
V
⎞
× ⎜1 − OUT ⎟ × RESR
fS × L1 ⎝
VIN ⎠
MP2364 can be optimized for a wide range of
capacitance and ESR values.
Compensation Components
The MP2364 employs current mode control on
each channel for easy compensation and fast
transient response. The system stability and
transient response are controlled through the
COMP pin. COMP pin is the output of the
internal transconductance error amplifier. A
series capacitor-resistor combination sets a
pole-zero
combination
to
control
the
characteristics of the control system.
The DC gain of the voltage feedback loop is
given by:
A VDC = R LOAD × G CS × A VEA ×
VFB
VOUT
Where AVEA is the error amplifier voltage gain,
GCS is the current sense transconductance and
RLOAD is the load resistor value.
The system has two poles of importance. One
is due to the compensation capacitor (C3) and
the output resistor of error amplifier, and the
other is due to the output capacitor and the load
resistor. These poles are located at:
fP1 =
G EA
2π × C3 × A VEA
fP2 =
1
2π × C2 × R LOAD
is
Where
GEA
transconductance.
the
error
amplifier
The system has one zero of importance, due to
the compensation capacitor (C3) and the
compensation resistor (R3). This zero is located
at:
f Z1 =
1
2π × C3 × R3
The system may have another zero of
importance, if the output capacitor has a large
capacitance and/or a high ESR value. The zero,
due to the ESR and capacitance of the output
capacitor,
is
located
at:
The characteristics of the output capacitor also
affect the stability of the regulation system. The
MP2364 Rev. 1.4
3/22/2006
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TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
fESR =
1
2π × C2 × R ESR
In this case (as shown in Figure 2), a third pole
set by the compensation capacitor (C6) and the
compensation resistor (R3) is used to
compensate the effect of the ESR zero on the
loop gain. This pole is located at:
fP3 =
1
2π × C6 × R3
The goal of compensation design is to shape
the converter transfer function to get a desired
loop gain. The system crossover frequency
where the feedback loop has the unity gain is
important.
Lower crossover frequencies result in slower
line and load transient responses, while higher
crossover frequencies could cause system
unstable. A good rule of thumb is to set the
crossover frequency to below one-tenth of the
switching
frequency.
To
optimize
the
compensation components for conditions not
listed in Table 2, the following procedure can be
used:
1. Choose the compensation resistor (R3) to set
the desired crossover frequency. Determine the
R3 value by the following equation:
R3 =
3. Determine if the second compensation
capacitor (C6) is required. It is required if the
ESR zero of the output capacitor is located at
less than half of the switching frequency, or the
following relationship is valid:
f
1
< S
2π × C2 × R ESR
2
If this is the case, then add the second
compensation capacitor (C6) to set the pole fP3
at the location of the ESR zero. Determine the
C6 value by the equation:
C6 =
C2 × R ESR
R3
Soft-Start
Each channel is soft-start controlled with the
SSA and SSB pins. Use capacitors to control
the ramp time using the equation:
RampTime = 2.2 × 9kΩ × C4
External Bootstrap Diode
It is recommended that an external bootstrap
diode be added when the system has a 5V
fixed input or the power supply generates a 5V
output. This helps improve the efficiency of the
regulator. The bootstrap diode can be a low
cost one such as IN4148 or BAT54.
5V
2π × C2 × f C VOUT
×
G EA × G CS
VFB
Where fC is the desired crossover frequency,
which is typically less than one tenth of the
switching frequency.
2. Choose the compensation capacitor (C3) to
achieve the desired phase margin. For
applications with typical inductor values, setting
the compensation zero, fZ1, to below one forth
of the crossover frequency provides sufficient
phase margin. Determine the C3 value by the
following equation:
C3 >
BSA/B
10nF
MP2364
SWA/B
MP2364_F02
Figure 2—External Bootstrap Diode
This diode is also recommended for high duty
cycle operation (when
VOUT
>65%) and high
VIN
output voltage (VOUT>12V) applications.
4
2π × R3 × f C
Where R3 is the compensation resistor value.
MP2364 Rev. 1.4
3/22/2006
www.MonolithicPower.com
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© 2006 MPS. All Rights Reserved.
9
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
TYPICAL APPLICATION CIRCUITS
12V
3.3V @ 1.5A
1
2
3
SSA
ENA
NC1
COMPA
BSA
FBA
4
C5A
INA
10nF 5
SWA
D1A
B230A
6
7
8
9
OFF ON
10
SGB
MP2364
PGB
PGA
SWB
SGA
INB
FBB
NC2
COMPB
BSB
ENB
SSB
20
OFF ON
19
C6A
82pF
18
17
16
D1B
B230A
15
14
13
C3A
2.2nF
2.5V @ 1.5A
C5B
10nF
12
11
C3B
3.3nF
MP2364_F03
Figure 3—2.5V @ 1.5A and 3.3V @ 1.5A Application Circuit
MP2364 Rev. 1.4
3/22/2006
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
10
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
PACKAGE INFORMATION
TSSOP20F
0.0256(0.650)TYP
0.004(0.090)
0.010(0.250)
GATE PLANE
0.105 (2.67)
0.118 (3.00)
pad width
0.169
0.177
0.244
0.260
(4.300)
(4.500)
(6.200)
(6.600)
0.004(0.090)
0o-8o
0.018(0.450)
0.030(0.750)
DETAIL "A"
0.039(1.000)REF
0.030(0.750)
PIN 1
IDENT.
0.030(0.750)
SEE DETAIL "B"
0.150 (3.80)
0.165 (4.19)
pad length
SEE DETAIL "A"
0.075(0.190)
0.012(0.300)
0.252 (6.400)
0.260 (6.600)
0.032(0.800)
0.041(1.050)
0.047(1.200)
max
0.007(0.190)
0.012(0.300)
0.004(0.090)
0.008(0.200)
0.004(0.090)
0.006(0.160)
SEATING PLANE
0.002(0.050)
0.006(0.150)
0.007(0.190)
0.010(0.250)
DETAIL "B"
NOTE:
1) Control dimension is in inches. Dimension in bracket is millimeters.
MP2364 Rev. 1.4
3/22/2006
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
11
TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
SOIC16
0.745(18.92)
0.765(19.43)
16
9
0.240(6.10)
0.260(6.60)
PIN 1 ID
1
8
TOP VIEW
0.320( 8.13)
0.400(10.16)
0.300(7.62)
0.325(8.26)
0.125(3.18)
0.145(3.68)
0.015(0.38)
0.035(0.89)
0.120(3.05)
0.140(3.56)
0.050(1.27)
0.065(1.65)
0.015(0.38)
0.021(0.53)
0.008(0.20)
0.014(0.36)
0.100(2.54)
BSC
FRONT VIEW
SIDE VIEW
NOTE:
1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN BRACKET IS IN MILLIMETERS.
2) PACKAGE LENGTH AND WIDTH DO NOT INCLUDE MOLD FLASH, OR PROTRUSIONS.
3) DRAWING CONFORMS TO JEDEC MS-001, VARIATION BB.
4) DRAWING IS NOT TO SCALE.
NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications.
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.
MP2364 Rev. 1.4
3/22/2006
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2006 MPS. All Rights Reserved.
12