FUJITSU SEMICONDUCTOR DATA SHEET DS04-27216-2E ASSP For Power Supply Applications BIPOLAR Switching Regulator Controller MB3817 ■ DESCRIPTION The MB3817 is a pulse width modulator (PWM) type switching regulator controller IC designed for low-voltage and high-speed operation. This can be used in applications as down-conversion or down/up-conversion (Zeta method). With fewer external components and faster operating speed, the MB3817 enables reduction in power supply unit size, making it ideal for use with internal power supplies in compact, high-performance portable devices. ■ FEATURES • • • • • • • • • Wide range of operating power supply voltages: 2.5 V to 18 V Built-in high-precision reference voltage generator: 1.5 V ± 2% High speed operation is possible: Max. 500 kHz Wide input voltage range of error amplifier: 0 to VCC – 0.9 V Built-in soft start function Built-in timer/latch-actuated short-circuiting protection circuit Totem-pole type output with adjustable on/off current (for PNP transistors) Built-in standby function Small package: SSOP-16P (FPT-16P-M05) ■ PACKAGE 16-pin Plastic SSOP (FPT-16P-M05) MB3817 ■ PIN ASSIGNMENT (TOP VIEW) CT 1 16 VREF RT 2 15 CTL +IN 3 14 CSCP −IN 4 13 CS FB 5 12 GND DTC 6 11 VE CB1 7 10 OUT CB2 8 9 V CC (FPT-16P-M05) 2 MB3817 ■ PIN DESCRIPTION Pin no. Pin name I/O Descriptions 1 CT — This pin connects to a capacitor for setting the triangular-wave frequency. 2 RT — This pin connects to a resistor for setting the triangular-wave frequency. 3 +IN I Error amplifier non-inverted input pin 4 –IN I Error amplifier inverted input pin 5 FB O Error amplifier output pin 6 DTC I Dead time control pin 7 CB1 — Boot capacitor connection pin 8 CB2 — Boot capacitor connection pin 9 VCC — Power supply pin 10 OUT O Totem-pole type output pin 11 VE — Output current setting pin 12 GND — Ground pin 13 CS — Soft start setting capacitor connection pin 14 CSCP — Short detection setting capacitor connection pin 15 CTL I Power supply control pin When this pin is High, IC is inactive state When this pin is Low, IC is standby state 16 VREF O Reference voltage output pin 3 MB3817 ■ BLOCK DIAGRAM CB1 OUT 7 FB 8 5 −IN +IN DTC CB2 4 Error − Amp. 3 + PWM 9 + Comp. + + − OFF current setting block VCC Q4 10 6 OUT CS CS 13 Q6 1µ Soft Start − Comp. + Q1 (0.9 V) − D1 (0.5 V) Q5 SCP Comp. 11 VE + 1.5 V SCP 1µ −1.4 V −1.0 V RS Latch OSC 1 2 CT 4 bias RT bias UVLO Q2 Q3 VCC Power Ref (1.5 V) ON/OFF 14 16 CSCP VREF 12 GND 15 CTL MB3817 ■ ABSOLUTE MAXIMUM RATINGS Parameter Symbol Condition Power supply voltage VCC — Power dissipation PD Storage temperature Tstg Ta +25°C — Rating Unit Min. Max. — 20 V — 440* mW –55 +125 °C * : The package is mounted on the epoxy board (10 cm × 10 cm). WARNING: Semiconductor devices can be permanently damaged by application of stress (voltage, current, temperature, etc.) in excess of absolute maximum ratings. Do not exceed these ratings. ■ RECOMMENDED OPERATING CONDITIONS Parameter Symbol Condition Value Min. Typ. Max. Unit Power supply voltage VCC — 2.5 6.0 18 V Reference voltage output current IOR — –1 — 0 mA Error amp. input voltage VIN — 0 — VCC – 0.9 V Control input voltage VCTL — 0 — 18 V Output current IO — 3 — 30 mA Timing capacitance CT — 150 — 1500 pF Timing resistance RT — 5.1 — 100 kΩ Oscillation frequency fOSC — 10 200 500 kHz Soft start capacitance CS — — 0.1 1.0 µF Short detection capacitance CSCP — — 0.1 1.0 µF Boot capacitance CB — — — 0.1 µF Operating temperature Ta — –40 +25 +85 °C WARNING: Recommended operating conditions are normal operating ranges for the semiconductor device. All the device’s electrical characteristics are warranted when operated within these ranges. Always use semiconductor devices within the recommended operating conditions. Operation outside these ranges may adversely affect reliability and could result in device failure. No warranty is made with respect to uses, operating conditions, or combinations not represented on the data sheet. Users considering application outside the listed conditions are advised to contact their FUJITSU representative beforehand. 5 MB3817 ■ ELECTRICAL CHARACTERISTICS (VCC = 6 V, Ta = +25°C) Symbol Pin no. Condition VREF 16 ∆VREF/ VREF Input stability Load stability Parameter Output voltage Output temperature stability Reference section (Ref) Short circuit output current Under voltage lockout protection section (UVLO) Reset voltage Unit Min. Typ. Max. — 1.47 1.50 1.53 V 16 Ta = –40°C to +85°C — 0.5* — % Line 16 VCC = 2.5 V to 18 V — 2 10 mV Load 16 IOR = 0 mA to –1 mA — 2 10 mV IOS 16 VREF = 1 V –10 –5 –2 mA VTH 13 VCC = — 2.0 2.3 V VTL 13 VCC = 1.5 1.8 — V VH 13 — 0.1 0.2 — V — Threshold voltage Hysteresis width Value VR 13 0.6 1.0 — V VT0 10 Duty cycle = 0 % 0.9 1.0 — V VT100 10 Duty cycle = 100 % — 1.4 1.5 V VSTB 13 — — 50 100 mV Charge current ICHG 13 — –1.4 –1.0 –0.6 µA Threshold voltage VTH 14 — 0.60 0.65 0.70 V VSTB 14 — — 50 100 mV VI 14 — — 50 100 mV Input source current II 14 — –1.4 –1.0 –0.6 µA Oscillator frequency fOSC 10 CT = 330 pF RT = 6.2 kΩ 450 500 550 kHz ∆f/fdv 10 VCC = 3.6 V to 16 V — 1 10 % ∆f/fdt 10 Ta = –40°C to +85°C — 1* — % Threshold voltage Soft start section Input standby (CS) voltage Input standby Short circuit detection section voltage (SCP) Input latch voltage Triangular waveform Frequency voltage oscillator section stability (OSC) Frequency temperature stability * : Standard design value. (Continued) 6 MB3817 (Continued) (VCC = 6 V, Ta = +25°C) Parameter Output section (OUT) Control section (CTL) Value Min. Typ. Max. Unit 3, 4 VFB = 1.2 V — — 10 mV Input offset current IIO 3, 4 VFB = 1.2 V — — 100 nA Input bias current II 3, 4 VFB = 1.2 V –200 –100 — nA 0 — VCC – 0.9 V VCM 3, 4 CMRR 5 DC 60 100 — dB Voltage gain AV 5 DC 60 100 — dB Frequency bandwidth BW 5 AV = 0 dB — 800* — kHz VOM+ 5 — 1.8 2.0 — V VOM– 5 — — 50 500 mV Output sink current IO+ 5 VFB = 1.2 V 60 120 — µA Output source current IO– 5 VFB = 1.2 V — –2.0 –0.6 mA Common mode rejection ratio — VT0 10 Duty cycle = 0 % 0.9 1.0 — V VT100 10 Duty cycle = 100 % — 1.4 1.5 V ON duty cycle Dtr 10 VDTC = VREF × 0.88 CT = 330 pF, RT = 6.2 kΩ 70 80 90 % Input current IDTC 6 VDTC = 0 V –500 –250 — nA VT0 10 Duty cycle = 0 % 0.9 1.0 — V VT100 10 Duty cycle = 100 % — 1.4 1.5 V Input sink current I I+ 5 — 60 120 — µA Input source current II– 5 — — –2.0 –0.6 mA Output sink current IO+ 10 RE = 15 kΩ 18 30 42 mA Output source current IO– 10 Duty — –100 –50 mA Standby leakage current ILO 10 VCC = 18 V, VO = 18 V — — 10 µA Input on condition VON 11 — 2.1 — 18 V Input off condition VOFF 11 — 0 — 0.7 V Threshold voltage PWM comparator section (PWM Comp.) Condition VIO Maximum output voltage width Dead time control section (DTC) Pin no. Input offset voltage Common mode input voltage range Error amp. section (Error Amp.) Symbol Threshold voltage 5% II 15 VCTL = 5 V — 100 200 µA Standby current ICCS 9 VCTL = 0 V — — 10 µA Power supply current ICC 9 Output “H” — 2.7 4.0 mA Input current * : Standard design value. 7 MB3817 ■ TYPICAL CHARACTERISTICS Power supply current vs. power supply voltage Reference voltage vs. power supply voltage 5 2.0 Reference voltage VREF (V) Power supply current ICC (mA) Ta = +25 °C 4 3 2 1 0 0 2 4 6 8 10 12 14 16 18 Ta = +25 °C IOR = 0 mA 1.5 1.0 0.5 0.0 20 0 2 4 Power supply voltage VCC (V) 6 8 10 12 14 16 18 20 Power supply voltage VCC (V) Reference voltage vs. ambient temperature 1.55 VCC = 6 V IOR = 0 mA Reference voltage VREF (V) 1.54 1.53 1.52 1.51 1.50 1.49 1.48 1.47 1.46 1.45 −60 −40 −20 0 20 40 60 80 100 Ambient temperature Ta (°C) Reference voltage vs. control voltage Control current vs. control voltage 500 Reference voltage VREF (V) Control current ICTL (µA) VCC = 6 V Ta = +25 °C IOR = 0 mA 1.7 1.6 1.5 1.4 VCC = 6 V Ta = +25 °C 400 300 200 100 1.3 0 0 1 2 3 Control voltage VCTL (V) 4 5 0 4 8 12 16 20 Control voltage VCTL (V) (Continued) 8 MB3817 10 M VCC = 6V Ta = +25 °C 1M 100 k CT = 150 pF 10 k CT = 1500 pF CT = 15000 pF 1k 1k 10 k 100 k 1M Timing resistance RT (Ω) Triangular wave maximum amplitude voltage vs. timing capacitance Triangular wave maximum amplitude voltage VCT (V) Triangular wave frequency fOSC (Hz) Triangular wave frequency vs. timing resistance 1.8 1.4 1.2 1.0 0.8 0.6 10 103 104 105 Triangular wave cycle vs. timing capacitance 100 VCC = 6 V Ta = +25 °C RT = 6.2 kΩ VDTC = VREF × 0.88 60 40 20 10 k 100 k 1M 10 M Triangular wave cycle tOSC (µsec) 1000 80 100 VCC = 6 V Ta = +25 °C RT = 6.2 kΩ 10 1 0.1 10 102 Triangular wave frequency fOSC (Hz) 103 104 105 Timing capacitance CT (pF) Frequency stability vs. ambient temperature 10.00 Frequency stability (%) Duty Dtr (%) 102 Timing capacitance CT (pF) Duty vs. triangular wave frequency 0 1k VCC = 6 V Ta = +25 °C RT = 6.2 kΩ 1.6 VCC = 6 V fOSC = 500 kHz (CT = 330 pF, RT = 6.2 kΩ) 5.00 0.00 −5.00 −10.00 −60 −40 −20 0 20 40 60 80 100 Ambient temperature Ta (°C) (Continued) 9 MB3817 (Continued) Error amp. frequency 50 Ta = +25 °C 40 30 180 VCC = 6 V 135 φ 10 11 kΩ 90 45 Av 0 φ (deg) 20 Av (dB) • Measurement circuit 225 0 −10 −45 −20 −90 −30 −135 −40 −180 −50 1k 240 kΩ − + 2.4 kΩ 4 − 10 µF 5 3 + VREF 11 kΩ Error Amp. −225 10 k 100 k 1M 10 M Frequency fOSC (Hz) 1.0 500 VCC = 6 V Ta = +25 °C 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 −10 −20 −30 −40 Output current setting pin current IE (mA) 10 Power dissipation vs. ambient temperature Power dissipation PD (mW) Output current setting pin voltage VE (V) Output current setting pin voltage vs. output current setting pin current −50 440 400 300 200 100 0 −40 −20 0 20 40 60 80 Ambient temperature Ta (°C) 100 120 MB3817 ■ FUNCTIONAL DESCRIPTION 1. Switching Regulator Functions (1) Reference voltage circuit (Ref) The reference voltage circuit generates a temperature-compensated stable voltage (.=.1.50 V). This reference voltage is used as the reference voltage and bias level for the power control unit. (2) Triangular-wave oscillator circuit By connecting a timing capacitor and a resistor to the CT (pin1) and the RT (pin2) terminals, it is possible to generate any desired triangular oscillation waveform. (3) Error amplifier The error amp. is an amplifier circuit that detects the output voltage from the switching regulator and produces the PWM control signal. The broad in-phase input voltage range of 0 V to Vcc – 0.9 V provides easy setting from external power supplies and enables use with applications such as DC motor speed control systems. Also, it is possible to provide stable phase compensation for a system by setting up any desired level of loop gain, by connecting feedback resistance and a capacitor between the error amp. output pin (FB pin (pin 5)) and the inverse input pin (–IN pin (pin 4)). (4) PWM comparator (PWM Comp.) This is a voltage comparator with one inverted input and three non-inverted inputs, and operates as a voltagepulse width modulator controlling output duty in relation to input voltage. The output transistor is turned on during the interval in which the triangular waveform is lower than any of three voltages: the error amp. output voltage (FB pin (pin 5)), soft start set voltage (CS pin (pin 13)), or dwell time setting voltage (DTC pin (pin 6)). (5) Output circuits (OUT) The output circuit has totem pole type configuration, and can drive an external PNP transistor. The on current value can be set up to a maximum of 30 mA using the resistance (RE) connected to the VE pin (pin 11). The off current is set by connecting a bootstrap capacitor CB between the CP1 pin (pin 7) and CP2 pin (pin 8). 2. Power Supply Control Functions The output is switched on and off according to the voltage level at the CTL pin (pin 15). CTL pin voltage level Channel on/off status L( 0.7 V) Standby mode* H( 2.1 V) Operating mode * : Supply current in standby mode is 10 µA or less. 3. Protective Circuit Functions (1) Soft start and short protection circuits (CS, SCP) Soft starting, by preventing a rush current at power-on, can be provided by connecting a capacitor CS to the CS pin (pin 13). After the soft start operation is completed, the CSCP pin (pin 14) is held at “L” level (standby voltage VSTB), which functions as short detection standby mode. If an output short causes the error amp. output to rise above 1.5 V, capacitor CSCP begins charging, and after reaching threshold voltage VTH of 0.65 V causes the OUT pin (pin 10) to be fixed at “H” level and the dwell time to be set to 100%, and the CSCP pin (pin 14) is held at “L” level. Once the protection circuit has been activated, the power supply must be reset to restore operation. 11 MB3817 (2) Low input voltage error prevention circuit (UVLO) Power-on surges and momentary drops in power supply voltage can cause errors in control IC operation, which can destroy or damage systems. The low input voltage error protection circuit compares the supply voltage to the internal reference voltage, and sets the OUT pin (pin 10) to “H” level in the event of a drop in supply voltage. Operation is restored when the power supply voltage returns above the threshold voltage of the low input voltage error prevention circuit. 12 MB3817 ■ SETTING OUTPUT VOLTAGE • Output voltage VO is plus V0+ R1 Error Amp. −IN 4 − 3 + +IN R2 V0+ = VREF R2 (R1 + R2) VREF • Output voltage VO is minus VREF R2 R Error Amp. −IN 4 − 3 + +IN R1 V0− = − VREF 2 × R2 (R1 + R2) + VREF R V0− 13 MB3817 ■ METHOD OF SETTING THE OUTPUT CURRENT The output circuit is comprised of a totem-pole configuration. Its output current waveform is such that the ONcurrent value is set by constant current and the OFF-current value is set by a time constant. These output currents are set using the equations below. ON current: IO+ [mA] .=. 500 (Voltage on output current-setting pin VE = 0.5 V) RE [Ω] OFF current: OFF-current time constant = proportional to the value of CB • Output circuit CB1 CB 7 8 CB2 Outside putting PNP transistor 9 OFF current setting block Q4 VCC OFF current 10 Q6 Q5 D1 (0.5 V) OUT ON current 11 RE VE • Output current waveform Output current ON current 0 OFF current t 14 MB3817 • Voltage and current waveforms on output pin VCC = 3 V 4 VO (V) 2 0 −2 −4 20 0 IO (mA) 40 −20 0 2 4 6 8 10 t (µs) • Measuring circuit diagram 7 8 9 CB1 CB 1000 pF CB2 VCC VCC 2S81121S U1FWJ44N (5.0 V) OUT RE 22 µF VE 16 Ω VO 35 kΩ 10 22 µF 15 kΩ 11 Pin 4 15 MB3817 ■ METHOD OF SETTING THE SHORT DETECTION TIME The error amp. output is connected to the inverted input of the short detector comparator circuit (SCP Comp.), where it is constantly compared to the reference voltage of approximately 1.5 V that is connected to the noninverted input. If the switching regulator load conditions are stabilized, the short detector comparator output is at “H” level, transistor Q3 is on, and the CSCP pin (pin14) holds the input standby voltage VSTB which is 50 mV. If load conditions change rapidly due to a cause such as a load short, so that output voltage falls, the short detector comparator circuit output changes to “L” level. When this happens, transistor Q3 turns off and the short detector capacitor CSCP connected externally to the CSCP pin starts charging from the input source current II, which is –1.0 µA. Short detection time (tPE) tPE [s] .=. 0.65 × CSCP [µF] When the short detector capacitor CSCP has been charged to the threshold voltage VTH, which is 0.65 V, the SR latch is set, and the external PNP transistor is turned off (setting dwell time to 100%). At this time, the SR latch input is closed, and the CSCP pin is set to input latch voltage VI which is 50 mV. • Short protection circuit FB 5 −IN +IN 4 − 3 + Outside putting PNP transistor Error Amp. + + + − PWM Comp. 9 OFF current setting block VCC Q4 10 OUT Q6 − Q5 SCP Comp. + 1.5 V 1µ bias RS Latch UVLO Q2 Q3 14 CSCP 16 D1 (0.5V) RE 11 VE MB3817 ■ TREATMENT WHEN NOT USING CSCP When you do not use the timer/latch-actuated short-circuiting protection circuit, connect the CSCP terminal (pin 14) to GND. • Treatment when not using CSCP 14 CSCP 17 MB3817 ■ METHOD OF SETTING SOFT START TIME To protect against surge currents when the IC is turned on, a soft start setting can be made by connecting a soft start capacitor (CS) to the CS pin (pin 13). When the IC starts up (CTL pin (pin 15) to “H” level, Vcc UVLO threshold voltage VTH) the transistor Q1 turns off and the soft start capacitor (CS) connected to the CS pin begins charging from the charge current ICHG which is –1.0 µA. At this time, if the CS pin voltage is less than 0.9 V, the soft start comparator circuit output goes to “H” level, transistor Q2 turns on and the CSCP pin (pin 14) holds input standby voltage VSTB which is 50 mV so that the short protection circuit is not activated. When the CS pin voltage is greater than or equal to 0.9 V, transistor Q2 turns off, the PWM comparator circuit compares the CS pin voltage with the triangular wave and changes the ON duty of the OUTPUT pin, thus achieving a soft start. Note that the soft start time is determined by the following formula. Soft start time (time before output ON duty reaches 50%) tS [ms] .=. 1.2 × CS [µF] • Soft start circuit Outside putting PNP transistor + + + − PWM Comp. 9 OFF current setting block VCC Q4 10 OUT 1µ Q6 CS 13 Q5 Q1 − Soft Start Comp. + (0.9 V) 1µ bias RS Latch UVLO Q2 Q3 14 CSCP 18 D1 (0.5V) RE 11 VE MB3817 ■ TREATMENT WHEN NOT USING CS When not using the soft start function, the CS pin (pin 13) should be left open. • When no soft start time is set Open 13 CS 19 MB3817 ■ METHOD OF SETTING THE DEAD TIME When the device is set for step-up inverted output based on the flyback method, the output transistor is fixed to a full-on state (ON-duty = 100 %) at power switch-on. To prevent this problem, you may determine the voltages on the DTC terminals (pin 6) from the VREF voltage so you can easily set the output transistor’s dead time (maximum ON-duty) independently for each channel as shown below. When the voltage on the DTC terminals (pin 6) is lower than the triangular-wave output voltage from the oscillator, the output transistor turns off. The dead time calculation formula assuming that triangular-wave amplitude ≅ 0.4 V and triangular-wave minimum voltage ≅ 1.4 V is given below. Duty (ON)MAX .=. Vdt – 1.0 V × 100 [%] 0.4 When you do not use these DTC terminals, connect them to VREF terminal. • When using DTC to set dead time 16 VREF Ra 6 Vdt Rb • When not using DTC to set dead time 16 VREF 6 20 DTC DTC MB3817 ■ EQUIVALENT SERIES RESISTOR AND STABILITY OF SMOOTHING CAPACITOR The equivalent series resistance (ESR) of a smoothing capacitor in a DC/DC converter greatly affects the phase characteristics of the loop depending on its value. System stability is improved by ESR because it causes the phase to lead that of the ideal capacitor in highfrequency regions. (See Figures 2 and 3) Conversely, if a low-ESR smoothing capacitor is used, system stability deteriorates. Therefore, use of a low-ESR semiconductor electrolytic capacitors (ex. OS–CON) or tantalum capacitors calls for careful attention. • Figure 1 Basic circuit of stepdown DC/DC converter L Tr RC V IN D RL C • Figure 2 Gain-Frequency characteristic • Figure 3 Phase-Frequency characteristic 0 20 −20 −40 −60 10 (2) (1) : RC = 0 Ω (2) : RC = 31 mΩ 100 (1) 1k 10 k Frequency f (Hz) Phase φ (deg) Gain AV (dB) 0 (2) −90 −180 100 k 10 (1) : RC = 0 Ω (2) : RC = 31 mΩ 100 (1) 1k 10 k 100 k Frequency f (Hz) 21 MB3817 (Reference Data) The phase margin is halved by changing the smoothing capacitor from an aluminium electrolytic capacitor (RC ~ 1.0 Ω) to a small-ESR semiconductor electrolytic capacitor (OS – CON; RC ~ 0.2 Ω). (See Figure 5 and 6.) • Figure 4 DC/DC converter AV – φ characteristic measuring circuit VOUT VO + CNF AV − φ characteristic between this interval − FB + −IN VIN +IN R2 R1 VREF Error amp. • Figure 5 Gain-Frequency characteristic Gain - frequency and phase frequency characteristics of Al electrolytic capacitor (DC/DC converter +5 V output) 60 VCC = 10 V RL = 25 Ω CP = 0.1 µF AV 180 VO φ 20 90 62 ° 0 0 −90 −20 −40 10 100 1k Phase φ (deg) Gain AV (dB) 40 + + Al electrolytic capacitor 220 µF (16 V) − RC ≅ 1.0 Ω : FOSC = 1 kHz GND −180 100 k 10 k Frequency f (Hz) • Figure 6 Phase-Frequency characteristic Gain - frequency and phase frequency characteristics of OS − CON (DC/DC converter +5 V output) 60 VCC = 10 V RL = 25 Ω CP = 0.1 µF AV VO 20 90 φ 27 ° 0 −20 −40 10 0 −90 100 1k Frequency f (Hz) 22 180 10 k −180 100 k Phase φ (deg) Gain AV (dB) 40 + + OS − CON 22 µF (16 V) − RC ≅ 0.2 Ω : fOSC = 1 kHz GND VIN 13 1000 pF 0.1 µF CS 6 DTC 15 kΩ 10 kΩ 5 0.047 µF 4 −IN 3 +IN FB 18 kΩ 1 CT OSC Q1 CS 1µ + − 2 RT 6.2 kΩ 1.0 V 1.4 V (0.9 V) + + − 1.5 V RS Latch bias Soft Start Comp. − Error Amp1 UVLO SCP Comp. + + + − 11 10 9 VE 47 Ω OUT 22 µF VCC CB2 CB1 1000 pF 22 µH 4.7 µF VO (3.3 V) 15 Ω 2SB1121S: SANYO Electric Co., Ltd. UIFWJ44N: TOSHIBA CORPORATION U1FWJ44N 22 µF 2SB1121S CTL 15 (note) Output ON/OFF signal ON : CTL = 5 V OFF : CTL = 0 V 12 GND VCC Power ON/OFF 1.5 V Ref bias 14 16 CSCP VREF Q3 SCP 1µ Q6 Q4 (0.5 V) OFF current setting block Q5 OUT 0.1 µF Q2 PWM Comp. 8 7 MB3817 ■ APPLICATION EXAMPLE 1. Step-down scheme 23 24 VIN 15 kΩ 18 kΩ CS 13 6 1000 pF 0.1 µF 10 kΩ DTC 5 0.047 µF 4 −IN 3 +IN FB 1 CT OSC Q1 CS 1µ + − 2 RT 6.2 kΩ 1.0 V RS Latch bias 1.5 V (0.9 V) 1.4 V + − + Soft Start Comp. − Error Amp1 UVLO SCP Comp. + + + − Q5 VCC 12 9 15 11 10 GND Power ON/OFF 1.5 V Ref bias Q6 (0.5 V) OFF current setting block 14 16 CSCP VREF Q3 SCP 1µ 0.1 µF Q2 PWM Comp. OUT 8 7 22 µF 4.7 µF VO (3.3 V) 15 Ω 2SB1121S: SANYO Electric Co., Ltd. UIFWJ44N: TOSHIBA CORPORATION U1FWJ44N 22 µH 2SB1121S 4.7 µF 22 µH (note) Output ON/OFF signal ON : CTL = 5 V OFF : CTL = 0 V CTL VE 47 Ω OUT 22 µF VCC CB2 CB1 1000 pF MB3817 2. Zeta scheme VIN 15 kΩ 35 kΩ R2 +IN −IN FB 6 3 4 5 1 µF 13 + CS CT OSC Q1 1µ 1 1000 pF CS 13 kΩ 1.2 kΩ DTC 0.047 µF R1 2 6.2 kΩ RT 1.5 V (0.9 V) −1.0 V RS Latch bias + + −1.4 V − Soft Start − Comp. Error Amp. UVLO SCP Comp. + + + − bias VCC D1 (0.5 V) Q6 Q4 12 9 8 7 15 11 10 GND Power Ref (1.5 V) ON/OFF Q5 OFF current setting block 14 16 CSCP VREF Q3 1µ SCP 2.2 µF Q2 PWM Comp. OUT 1000 pF 22 µF VO (5.0 V) 2SB1121S: SANYO Electric Co., Ltd. UIFWJ44N: TOSHIBA CORPORATION 22 µF 2SB1121S U1FWJ44N CTL (note) Output ON/OFF signal ON : CTL = 5 V OFF : CTL = 0 V VE OUT 22 µF RE 16 Ω VCC CB2 CB1 CB MB3817 3. Flyback scheme 25 MB3817 ■ USAGE PRECAUTIONS 1. Never use setting exceeding maximum rated conditions. Exceeding maximum rated conditions may cause permanent damage to the LSI. Also, it is recommended that recommended operating conditions be observed in normal use. Exceeding recommended operating conditions may adversely affect LSI reliability. 2. Use this device within recommended operating conditions. Recommended operating conditions are values within which normal LSI operation is warranted. Standard electrical characteristics are warranted within the range of recommended operating conditions and within the listed conditions for each parameter. 3. Printed circuit board ground lines should be set up with consideration for common impedance. 4. Take appropriate static electricity measures. • • • • 26 Containers for semiconductor materials should have anti-static protection or be made of conductive material. After mounting, printed circuit boards should be stored and shipped in conductive bags or containers. Work platforms, tools, and instruments should be properly grounded. Working personnel should be grounded with resistance of 250 kΩ to 1 MΩ between body and ground. MB3817 ■ ORDERING INFORMATION Part number MB3817PFV Package Remarks 16-pin Plastic SSOP (FPT-16P-M05) 27 MB3817 ■ PACKAGE DIMENSION 16-pin Plastic SSOP (FPT-16P-M05) *: These dimensions do not include resin protrusion. +0.20 * 5.00±0.10(.197±.004) 1.25 –0.10 +.008 .049 –.004 (Mounting height) 0.10(.004) INDEX * 4.40±0.10 (.173±.004) 0.65±0.12 (.0256±.0047) 4.55(.179)REF C 28 1994 FUJITSU LIMITED F16013S-2C-4 +0.10 6.40±0.20 (.252±.008) 5.40(.213) NOM "A" +0.05 0.22 –0.05 0.15 –0.02 +.004 –.002 .006 –.001 .009 Details of "A" part +.002 0.10±0.10(.004±.004) (STAND OFF) 0 10° 0.50±0.20 (.020±.008) Dimensions in mm (inches) MB3817 FUJITSU LIMITED For further information please contact: Japan FUJITSU LIMITED Corporate Global Business Support Division Electronic Devices KAWASAKI PLANT, 4-1-1, Kamikodanaka Nakahara-ku, Kawasaki-shi Kanagawa 211-8588, Japan Tel: 81(44) 754-3763 Fax: 81(44) 754-3329 http://www.fujitsu.co.jp/ North and South America FUJITSU MICROELECTRONICS, INC. Semiconductor Division 3545 North First Street San Jose, CA 95134-1804, USA Tel: (408) 922-9000 Fax: (408) 922-9179 Customer Response Center Mon. - Fri.: 7 am - 5 pm (PST) Tel: (800) 866-8608 Fax: (408) 922-9179 http://www.fujitsumicro.com/ Europe FUJITSU MIKROELEKTRONIK GmbH Am Siebenstein 6-10 D-63303 Dreieich-Buchschlag Germany Tel: (06103) 690-0 Fax: (06103) 690-122 http://www.fujitsu-ede.com/ Asia Pacific FUJITSU MICROELECTRONICS ASIA PTE LTD #05-08, 151 Lorong Chuan New Tech Park Singapore 556741 Tel: (65) 281-0770 Fax: (65) 281-0220 http://www.fmap.com.sg/ F9812 FUJITSU LIMITED Printed in Japan All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales representatives before ordering. The information and circuit diagrams in this document are presented as examples of semiconductor device applications, and are not intended to be incorporated in devices for actual use. Also, FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use of this information or circuit diagrams. FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and other office equipment, industrial, communications, and measurement equipment, personal or household devices, etc.). CAUTION: Customers considering the use of our products in special applications where failure or abnormal operation may directly affect human lives or cause physical injury or property damage, or where extremely high levels of reliability are demanded (such as aerospace systems, atomic energy controls, sea floor repeaters, vehicle operating controls, medical devices for life support, etc.) are requested to consult with FUJITSU sales representatives before such use. The company will not be responsible for damages arising from such use without prior approval. Any semiconductor devices have an inherent chance of failure. You must protect against injury, damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of over-current levels and other abnormal operating conditions. If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign Exchange and Foreign Trade Law of Japan, the prior authorization by Japanese government will be required for export of those products from Japan.