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LTC3868

3868fd

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

Low I

, Dual

2-Phase Synchronous

Step-Down Controller

High Efﬁ ciency Dual 8.5V/3.3V Step-Down Converter

Low Operating I

: 170μA (One Channel On)

Wide Output Voltage Range: 0.8V ≤ V

OUT

≤ 14V

Wide V

Range: 4V to 24V

SENSE

or DCR Current Sensing

Out-of-Phase Controllers Reduce Required Input

Capacitance and Power Supply Induced Noise

OPTI-LOOP

Compensation Minimizes C

OUT

Phase-Lockable Frequency (75kHz to 850kHz)

Programmable Fixed Frequency (50kHz to 900kHz)

Selectable Continuous, Pulse-Skipping or

Burst Mode

Operation at Light Loads

Very Low Dropout Operation: 99% Duty Cycle

Adjustable Output Voltage Soft-Start

Power Good Output Voltage Monitor

Output Overvoltage Protection

Output Latchoff Protection During Short Circuit

Low Shutdown I

: 8µA

Internal LDO Powers Gate Drive from V

or EXTV

No Current Foldback During Start-Up

Small 5mm × 5mm QFN Package

Notebook and Palmtop Computers

Portable Instruments

Battery Operated Digital Devices

Distributed DC Power Systems

L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, PolyPhase, µModule, Linear Technology and the Linear

logo are registered trademarks and No R

SENSE

and UltraFast are trademarks of Linear Technology

Corporation. All other trademarks are the property of their respective owners. Protected by U.S.

Patents, including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258.

Efﬁ ciency and Power Loss

vs Load Current

The LTC

3868 is a high performance dual step-down

switching regulator controller that drives all N-channel

synchronous power MOSFET stages. A constant frequency

current mode architecture allows a phase-lockable fre-

quency of up to 850kHz. Power loss and noise due to the

input capacitor ESR are minimized by operating the two

controller outputs out of phase.

The 170A no-load quiescent current extends operating life in

battery-powered systems. OPTI-LOOP compensation allows

the transient response to be optimized over a wide range of

output capacitance and ESR values. The LTC3868 features a

precision 0.8V reference and a power good output indicator. A

wide 4V to 24V input supply range encompasses a wide range

of intermediate bus voltages and battery chemistries.

Independent soft-start pins for each controller ramp the

output voltages during start-up. Current foldback limits

MOSFET heat dissipation during short-circuit conditions.

The output short-circuit latchoff feature further protects

the circuit in short-circuit conditions.

For a leaded 28-lead SSOP package with a ﬁ xed current

limit and one PGOOD output, without phase modulation

or a clock output, see the LTC3868-1 data sheet.

0.1µF

62.5k

3.3µH

680pF

150µF

4.7µF

22µF

50V

0.007Ω

20k

15k

OUT1

3.3V

150µF

0.1µF

193k

7.2µH

680pF

0.01Ω

20k

15k

OUT2

8.5V

3.5A

TG1 TG2

BOOST1 BOOST2

SW1 SW2

BG1 BG2

SGND

PGND

SENSE1

SENSE2

SENSE1

–

SENSE2

–

FB1

FB2

TH1

TH2

INTV

SS1 SS2

9V TO 24V

3868 TA01

0.1µF

LTC3868

OUTPUT CURRENT (A)

0.0001

EFFICIENCY (%)

POWER LOSS (mW)

0.001 0.01 0.1 1 10

3868 TA01b

100

1000

0.1

10000

EFFICIENCY

POWER LOSS

= 12V

OUT

= 3.3V

FIGURE 12 CIRCUIT

Summary of content (38 pages)

PAGE 1
LTC3868 Low IQ, Dual 2-Phase Synchronous Step-Down Controller DESCRIPTION FEATURES n n n n n n n n n n n n n n n n n n The LTC®3868 is a high performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. Power loss and noise due to the input capacitor ESR are minimized by operating the two controller outputs out of phase.
PAGE 2
LTC3868 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Input Supply Voltage (VIN) ......................... –0.3V to 28V Topside Driver Voltages BOOST1, BOOST2 ................................. –0.3V to 34V Switch Voltage (SW1, SW2) ........................ –5V to 28V PLLIN/MODE (BOOST1-SW1), (BOOST2-SW2) ................ –0.3V to 6V RUN1, RUN2 ................................................ –0.3V to 8V Maximum Current Sourced into Pin from Source >8V ...............................................
PAGE 3
LTC3868 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the full operating temperature range, otherwise speciﬁcations are at TA = 25°C. VIN = 12V, VRUN1,2 = 5V, EXTVCC = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VLOADREG Output Voltage Load Regulation (Note4) Measured in Servo Loop, ∆ITH Voltage = 1.2V to 0.7V (Note4) Measured in Servo Loop, ∆ITH Voltage = 1.2V to 2V MIN TYP MAX l 0.01 0.1 % l –0.01 –0.
PAGE 4
LTC3868 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the full operating temperature range, otherwise speciﬁcations are at TA = 25°C. VIN = 12V, VRUN1,2 = 5V, EXTVCC = 0V unless otherwise noted.
PAGE 5
LTC3868 TYPICAL PERFORMANCE CHARACTERISTICS Efﬁciency and Power Loss vs Output Current Efﬁciency vs Output Current 100 90 100 60 50 10 40 30 Burst Mode OPERATION PULSESKIPPING FCM 20 10 0.01 0.1 1 OUTPUT CURRENT (A) 1 EFFICIENCY (%) 70 0.001 80 1000 POWER LOSS (mW) EFFICIENCY (%) FIGURE 12 CIRCUIT 90 VIN = 12V VOUT = 3.3V 80 0 0.0001 100 10000 VIN = 5V 70 VIN = 12V 60 50 40 30 20 10 0.1 10 0 0.0001 VOUT = 3.3V FIGURE 12 CIRCUIT 0.001 0.01 0.
PAGE 6
LTC3868 TYPICAL PERFORMANCE CHARACTERISTICS Total Input Supply Current vs Input Voltage SUPPLY CURRENT (μA) 300 300μA LOAD 250 200 NO LOAD 150 100 50 0 10 5 15 25 20 INPUT VOLTAGE (V) 5.2 5.4 5.2 INTVCC 5.0 EXTVCC RISING 4.8 EXTVCC FALLING 4.6 5.0 80 55 30 TEMPERATURE (°C) 5 ILIM = GND ILIM = FLOAT ILIM = INTVCC –20 –150 –200 –250 –300 –350 –400 –450 –500 –550 5% DUTY CYCLE 0 0.2 0.4 0.6 0.8 1.0 ITH PIN VOLTAGE 1.2 –600 1.
PAGE 7
LTC3868 TYPICAL PERFORMANCE CHARACTERISTICS Soft-Start Pull-Up Current vs Temperature 1.40 808 REGULATED FEEDBACK VOLTAGE (mV) 1.20 1.35 1.15 1.30 1.10 RUN PIN VOLTAGE (V) SS PULL-UP CURRENT (μA) Regulated Feedback Voltage vs Temperature Shutdown (RUN) Threshold vs Temperature 1.05 1.00 0.95 0.90 1.25 1.20 1.15 1.10 1.05 1.00 0.85 0.95 0.80 –45 –20 80 55 30 TEMPERATURE (°C) 5 105 0.
PAGE 8
LTC3868 TYPICAL PERFORMANCE CHARACTERISTICS Latchoff Thresholds vs Temperature INTVCC and EXTVCC vs Load Current 5.20 2.3 VIN = 12V 2.2 2.1 INTVCC VOLTAGE (V) INTVCC VOLTAGE (V) 5.15 5.10 EXTVCC = 0V 5.05 EXTVCC = 8V 5.00 ARMING THRESHOLD 2.0 1.9 1.8 1.7 1.6 LATCH-OFF THRESHOLD 1.5 1.4 1.3 4.95 0 20 40 60 80 100 120 140 160 180 200 LOAD CURRENT (mA) 3868 G26 1.
PAGE 9
LTC3868 PIN FUNCTIONS RUN1, RUN2 (Pin 7, Pin 8): Digital Run Control Inputs for Each Controller. Forcing either of these pins below 1.26V shuts down that controller. Forcing both of these pins below 0.7V shuts down the entire LTC3868, reducing quiescent current to approximately 8μA. Do not ﬂoat these pins. ILIM (Pin 28): Current Comparator Sense Voltage Range Inputs. Tying this pin to SGND, FLOAT or INTVCC sets the maximum current sense threshold to one of three different levels for both comparators.
PAGE 10
LTC3868 FUNCTIONAL DIAGRAM VIN INTVCC PGOOD1 27 0.88V PHASMD CLKOUT 3 4 DUPLICATE FOR SECOND CONTROLLER CHANNEL + – VFB1 DROP OUT DET + – + PGOOD2 14 0.72V 0.88V S Q R Q TOP BOT SWITCH LOGIC BOT – SHDN INTVCC + 0.72V TG 26, 15 CB D CIN BG 23, 18 COUT PGND – 20μA FREQ DB SW 25, 16 TOP ON VFB2 BOOST 24, 17 VOUT 21 VCO 2 CLK2 0.425V CLK1 + SLEEP RSENSE L – ICMP PFD + – CLP –+ +– IR – SENSE+ 32, 10 + 3mV SYNC DET PLLIN/MODE 2.7V 0.
PAGE 11
LTC3868 OPERATION (Refer to the Functional Diagram) The LTC3868 uses a constant frequency, current mode step-down architecture with the two controller channels operating 180 degrees out of phase. During normal operation, each external top MOSFET is turned on when the clock for that channel sets the RS latch, and is turned off when the main current comparator, ICMP, resets the RS latch.
PAGE 12
LTC3868 OPERATION (Refer to the Functional Diagram) SS voltage has not yet reached 2V), a safe, low output current is provided due to internal current foldback and actual power wasted is low due to the efﬁcient nature of the current mode switching regulator. Foldback current limiting is disabled during the soft-start interval (as long as the VFB voltage is keeping up with the SS voltage). INTVCC SS VOLTAGE 2V 1.5V 0.
PAGE 13
LTC3868 OPERATION (Refer to the Functional Diagram) When a controller is enabled for Burst Mode operation, the inductor current is not allowed to reverse. The reverse current comparator, IR, turns off the bottom external MOSFET just before the inductor current reaches zero, preventing it from reversing and going negative. Thus, the controller is in discontinuous operation.
PAGE 14
LTC3868 OPERATION (Refer to the Functional Diagram) between the two internal controllers, as summarized in Table 1. The phases are calculated relative to the zero degrees phase being deﬁned as the rising edge of the top gate driver output of controller 1 (TG1).
PAGE 15
LTC3868 OPERATION (Refer to the Functional Diagram) meaning that the actual power wasted is reduced by a factor of 2.66. The reduced input ripple voltage also means less power is lost in the input power path, which could include batteries, switches, trace/connector resistances and protection circuitry. Improvements in both conducted and radiated EMI also directly accrue as a result of the reduced RMS input current and voltage.
PAGE 16
LTC3868 APPLICATIONS INFORMATION The Typical Application on the ﬁrst page is a basic LTC3868 application circuit. LTC3868 can be conﬁgured to use either DCR (inductor resistance) sensing or low value resistor sensing. The choice between the two current sensing schemes is largely a design trade off between cost, power consumption and accuracy. DCR sensing is becoming popular because it saves expensive current sensing resistors and is more power efﬁcient, especially in high current applications.
PAGE 17
LTC3868 APPLICATIONS INFORMATION duty factor. A curve is provided in the Typical Performance Characteristics section to estimate this reduction in peak output current depending upon the operating duty factor.
PAGE 18
LTC3868 APPLICATIONS INFORMATION The equivalent resistance R1||R2 is scaled to the room temperature inductance and maximum DCR: R1|| R2 = L (DCR at 20°C) • C1 The sense resistor values are: R1= R1|| R2 R1• RD ; R2 = RD 1– RD The maximum power loss in R1 is related to duty cycle, and will occur in continuous mode at the maximum input voltage: PLOSS R1= ( VIN(MAX) – VOUT ) • VOUT R1 Accepting larger values of ∆IL allows the use of low inductances, but results in higher output voltage ripple and greater
PAGE 19
LTC3868 APPLICATIONS INFORMATION Pin Connection). Consequently, logic-level threshold MOSFETs must be used in most applications. The only exception is if low input voltage is expected (VIN < 4V); then, sub-logic level threshold MOSFETs (VGS(TH) < 3V) should be used. Pay close attention to the BVDSS speciﬁcation for the MOSFETs as well; many of the logic-level MOSFETs are limited to 30V or less.
PAGE 20
LTC3868 APPLICATIONS INFORMATION large voltage transients, a low ESR capacitor sized for the maximum RMS current of one channel must be used. The maximum RMS capacitor current is given by: CIN Required IRMS ≈ 1/ 2 IMAX ⎡ VOUT ) ( VIN – VOUT )⎤⎦ (1) ( ⎣ VIN Equation 1 has a maximum at VIN = 2VOUT , where IRMS = IOUT/2. This simple worst-case condition is commonly used for design because even signiﬁcant deviations do not offer much relief.
PAGE 21
LTC3868 APPLICATIONS INFORMATION Soft-start is enabled by simply connecting a capacitor from the SS pin to ground, as shown in Figure 7. An internal 1μA current source charges the capacitor, providing a linear ramping voltage at the SS pin. The LTC3868 will regulate the VFB pin (and hence VOUT) according to the voltage on the SS pin, allowing VOUT to rise smoothly from 0V to its ﬁnal regulated value.
PAGE 22
LTC3868 APPLICATIONS INFORMATION The following list summarizes the four possible connections for EXTVCC: 1. EXTVCC Left Open (or Grounded). This will cause INTVCC to be powered from the internal 5.1V regulator resulting in an efﬁciency penalty of up to 10% at high input voltages. 2. EXTVCC Connected Directly to VOUT . This is the normal connection for a 5V to 14V regulator and provides the highest efﬁciency. 3. EXTVCC Connected to an External Supply.
PAGE 23
LTC3868 APPLICATIONS INFORMATION A comparator monitors the output for overvoltage conditions. The comparator detects faults greater than 10% above the nominal output voltage. When this condition is sensed, the top MOSFET is turned off and the bottom MOSFET is turned on until the overvoltage condition is cleared. The bottom MOSFET remains on continuously for as long as the overvoltage condition persists; if VOUT returns to a safe level, normal operation automatically resumes.
PAGE 24
LTC3868 APPLICATIONS INFORMATION Minimum On-Time Considerations Minimum on-time, tON(MIN), is the smallest time duration that the LTC3868 is capable of turning on the top MOSFET. It is determined by internal timing delays and the gate charge required to turn on the top MOSFET.
PAGE 25
LTC3868 APPLICATIONS INFORMATION 4. Transition losses apply only to the topside MOSFET(s), and become signiﬁcant only when operating at high input voltages (typically 15V or greater). Transition losses can be estimated from: Transition Loss = (1.7) • VIN • 2 • IO(MAX) • CRSS • f Other hidden losses such as copper trace and internal battery resistances can account for an additional 5% to 10% efﬁciency degradation in portable systems.
PAGE 26
LTC3868 APPLICATIONS INFORMATION CLOAD to COUT is greater than 1:50, the switch rise time should be controlled so that the load rise time is limited to approximately 25 • CLOAD. Thus a 10μF capacitor would require a 250μs rise time, limiting the charging current to about 200mA. The power dissipation on the topside MOSFET can be easily estimated. Choosing a Fairchild FDS6982S dual MOSFET results in: RDS(ON) = 0.035Ω/0.022Ω, CMILLER = 215pF.
PAGE 27
LTC3868 APPLICATIONS INFORMATION PC Board Layout Checklist When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the IC. These items are also illustrated graphically in the layout diagram of Figure 10. Figure 11 illustrates the current waveforms present in the various branches of the 2-phase synchronous regulators operating in the continuous mode. Check the following in your layout: 1.
PAGE 28
LTC3868 APPLICATIONS INFORMATION ITH1 SS1 LTC3868 PGOOD2 VFB1 PGOOD1 RPU2 VPULL-UP (<6V) PGOOD2 RPU1 VPULL-UP (<6V) PGOOD1 L1 SENSE1+ TG1 SENSE1– SW1 VOUT1 CB1 FREQ PHASMD RSENSE M1 BOOST1 M2 D1 BG1 CLKOUT PLLIN/MODE RUN1 VIN CVIN RIN GND + INTVCC SENSE2+ BG2 VOUT1 CINTVCC VIN CIN COUT2 1μF CERAMIC M3 BOOST2 + EXTVCC SENSE2– VFB2 COUT1 PGND RUN2 SGND 1μF CERAMIC + fIN M4 D2 CB2 ITH2 SS2 SW2 RSENSE TG2 VOUT2 L2 3868 F10 Figure 10.
PAGE 29
LTC3868 APPLICATIONS INFORMATION SW1 L1 D1 RSENSE1 VOUT1 COUT1 RL1 VIN RIN CIN SW2 BOLD LINES INDICATE HIGH SWITCHING CURRENT. KEEP LINES TO A MINIMUM LENGTH. D2 L2 RSENSE2 VOUT2 COUT2 RL2 3868 F11 Figure 11.
PAGE 30
LTC3868 APPLICATIONS INFORMATION Reduce VIN from its nominal level to verify operation of the regulator in dropout. Check the operation of the undervoltage lockout circuit by further lowering VIN while monitoring the outputs to verify operation. Investigate whether any problems exist only at higher output currents or only at higher input voltages.
PAGE 31
LTC3868 TYPICAL APPLICATIONS RB1 215k INTVCC CF1 15pF LTC3868 SENSE1+ PGOOD2 C1 1nF RA1 68.1k SENSE1– VFB1 CITH1A 150pF 100k 100k PGOOD1 MBOT1 BG1 SW1 ITH1 RSENSE1 6mΩ CB1 0.47μF BOOST1 RITH1 15k CITH1 820pF COUT1 150μF VOUT1 3.3V 5A MTOP1 TG1 D1 CSS1 0.1μF VIN SS1 INTVCC ILIM PHASMD CLKOUT PGND PLLIN/MODE SGND TG2 EXTVCC RUN1 BOOST2 RUN2 FREQ CIN 22μF SS2 SW2 ITH2 BG2 VIN 9V TO 24V CINT 4.7μF D2 MTOP2 CB2 0.47μF L2 7.2μH CSS2 0.1μF CITH2 680pF L1 3.
PAGE 32
LTC3868 TYPICAL APPLICATIONS High Efﬁciency Dual 2.5V/3.3V Step-Down Converter RB1 143k INTVCC CF1 22pF C1 1nF RA1 68.1k LTC3868 SENSE1+ PGOOD2 SENSE1– VFB1 CITH1A 100pF 100k 100k PGOOD1 MBOT1 BG1 SW1 ITH1 RSENSE1 6mΩ CB1 0.47μF BOOST1 RITH1 22k CITH1 820pF COUT1 150μF VOUT1 2.5V 5A MTOP1 TG1 D1 CSS1 0.01μF VIN SS1 INTVCC ILIM PHASMD CLKOUT PGND PLLIN/MODE SGND TG2 EXTVCC RUN1 BOOST2 RUN2 FREQ CIN 22μF SS2 SW2 ITH2 BG2 VIN 4V TO 24V CINT 4.7μF D2 MTOP2 CB2 0.47μF L2 3.2μH CSS2 0.
PAGE 33
LTC3868 TYPICAL APPLICATIONS High Efﬁciency Dual 12V/5V Step-Down Converter RB1 475k CF1 33pF RA1 34k C1 1nF 100k INTVCC SENSE1+ PGOOD2 SENSE1– PGOOD1 100k VFB1 MBOT1 BG1 CITH1A 100pF SW1 LTC3868 CSS1 0.01μF D1 VIN SS1 INTVCC ILIM PHASMD CLKOUT PGND PLLIN/MODE SGND TG2 EXTVCC RUN1 BOOST2 RUN2 FREQ RFREQ 60k CIN 22μF SS2 SW2 ITH2 BG2 VIN 12.5V TO 24V CINT 4.7μF D2 MTOP2 CB2 0.47μF L2 4.3μH CSS2 0.
PAGE 34
LTC3868 TYPICAL APPLICATIONS High Efﬁciency Dual 1V/1.2V Step-Down Converter RB1 28.7k CF1 56pF RA1 115k C1 1nF 100k INTVCC SENSE1+ PGOOD2 SENSE1– PGOOD1 100k VFB1 L1 MBOT1 0.47μH BG1 CITH1A 200pF SW1 CITH1 1000pF CSS1 0.01μF RFREQ 60k MTOP1 TG1 ITH1 RSENSE1 3mΩ CB1 0.47μF BOOST1 RITH1 3.93k LTC3868 VIN SS1 INTVCC ILIM PHASMD CLKOUT PGND PLLIN/MODE SGND TG2 EXTVCC RUN1 BOOST2 RUN2 FREQ CIN 22μF SS2 SW2 ITH2 BG2 VIN 12V CINT 4.7μF D2 MTOP2 CB2 0.47μF L2 0.
PAGE 35
LTC3868 TYPICAL APPLICATIONS High Efﬁciency Dual 1V/1.2V Step-Down Converter with Inductor DCR Current Sensing RS1 1.18k RB1 28.7k CF1 56pF RA1 115k C1 0.1μF SENSE1+ PGOOD2 SENSE1– PGOOD1 INTVCC 100k 100k CITH1A 200pF SW1 CITH1 1000pF CSS1 0.01μF RFREQ 65k MTOP1 TG1 ITH1 COUT1 220μF ×2 CB1 0.47μF BOOST1 RITH1 3.93k LTC3868 VIN SS1 INTVCC ILIM PHASMD CLKOUT PGND PLLIN/MODE SGND TG2 EXTVCC RUN1 BOOST2 RUN2 FREQ CIN 22μF SS2 SW2 ITH2 BG2 VIN 12V CINT 4.7μF D2 MTOP2 CB2 0.47μF L2 0.
PAGE 36
LTC3868 PACKAGE DESCRIPTION UH Package 32-Lead Plastic QFN (5mm × 5mm) (Reference LTC DWG # 05-08-1693 Rev D) 0.70 p0.05 5.50 p0.05 4.10 p0.05 3.45 p 0.05 3.50 REF (4 SIDES) 3.45 p 0.05 PACKAGE OUTLINE 0.25 p 0.05 0.50 BSC RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 p 0.10 (4 SIDES) BOTTOM VIEW—EXPOSED PAD 0.75 p 0.05 R = 0.05 TYP 0.00 – 0.05 PIN 1 NOTCH R = 0.30 TYP OR 0.35 s 45o CHAMFER R = 0.115 TYP 31 32 0.40 p 0.10 PIN 1 TOP MARK (NOTE 6) 1 2 3.
PAGE 37
LTC3868 REVISION HISTORY (Revision history begins at Rev B) REV DATE DESCRIPTION B 12/09 Change to Absolute Maximum Ratings PAGE NUMBER 2 Change to Electrical Characteristics 3 Change to Typical Performance Characteristics Change to Pin Functions Text Changes to Operation Section Text Changes to Applications Information Section 6 8, 9 11, 12, 13 21, 22, 23, 26 Change to Table 2 23 Change to Figure 10 28 Changes to Related Parts 38 C 08/10 Change to Electrical Characteristics 3 Added T
PAGE 38
LTC3868 TYPICAL APPLICATION High Efﬁciency 2-Phase 12V/150W Step-Down Converter RB1 698k CF1 10pF RA1 49.9k SENSE1+ C1 1nF SENSE1– 100k INTVCC PGOOD2 100k PGOOD1 VFB1 MBOT1 BG1 CITH1A 68pF L1 6μH 10μF 16V SW1 CITH1 3300pF SS1 ITH1 VFB1 D1 LTC3868 CSS1 0.1μF VOUT VIN SS1 INTVCC ILIM PHASMD CLKOUT PGND PLLIN/MODE SGND TG2 EXTVCC RUN1 BOOST2 RUN2 FREQ SW2 SS2 ITH2 CIN 10μF 50V CINT 4.7μF 10μF 50V VIN 19V TO 24V D2 MTOP2 CB2 0.