MP1400 7V Input, 0.6A Peak, 1.5MHz Negative DCDC Power Converter In 8-ball CSP Package The Future of Analog IC Technology DESCRIPTION FEATURES The MP1400 is a monolithic negative DCDC power converter with built-in internal power MOSFET. The DC-DC IC has a tiny surface mount 0.8mm x 1.6mm 8-ball CSP package. It achieves up to 600mA peak output current from a 2.7V to 7V input voltage. The output voltage can be regulated from -0.9V to -6V. The 1500 kHz switching frequency allows for smaller external components producing a compact solution for a wide range of load currents. The internal compensation and soft start minimizes the external component count and limits the inrush current during startup. Fault condition protection includes cycle-bycycle current limiting and thermal shutdown. Wide 2.7V to 7V Operating Input Range Output Adjustable from -0.9V to -6V Up to 600mA Peak Output Current 300mΩ High Side MOSFET On Resistance Default 1.5MHz Switching Frequency Ground Reference Enable Cycle-by-Cycle Over Current Protection Short Circuit Protect with Hiccup Mode Output Voltage Discharge Output Over Voltage Protection Available in a 0.8mm x 1.6mm 8-ball CSP Package APPLICATIONS General Negative Voltage HDD Small OLED Panel All MPS parts are lead-free, halogen free, and adhere to the RoHS directive. For MPS green status, please visit MPS website under Quality Assurance. “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION L1 4.7uH VIN C1A 10uF 16V GND IN SW MP1400 GND GND EN R3 100K GND D1 MBR230 C2A 22uF 16V VOUT EN VOUT R1 105K FB GND REF R2 24.9K GND MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 1 MP1400 – NEGATIVE DCDC POWER CONVERTER ORDERING INFORMATION Part Number* MP1400GC Package CSP 0.8mm x 1.6mm Top Marking BT * For Tape & Reel, add suffix –Z (e.g. MP1400GC–Z); PACKAGE REFERENCE 1 2 A REF FB B EN VOUT C GND GND D SW IN CSP (0.8mm x 1.6mm) ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply Voltage VIN ...................................... 7.5V VSW ...................................................................... VOUT-0.7V (-8V for <10ns) to 8V (9V for <10ns) Output Voltage VOUT ................................... -6.5V All Other Pins ................................-0.3V to 6.5 V Junction Temperature ...............................150C Lead Temperature ....................................260C (2) Continuous Power Dissipation (TA = +25°C) ……….….. ............................................... 0.75W Storage Temperature............... -65C to +150C CSP8 …………………………… 170…..na…°C/W Recommended Operating Conditions (3) Supply Voltage VIN .............................2.7V to 7V Output Voltage VOUT ........................ -0.9V to -6V Operating Junction Temp. (TJ). -40°C to +125°C MP1400 Rev.1.1 5/27/2015 (4) θJA θJC 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. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 2 MP1400 – NEGATIVE DCDC POWER CONVERTER ELECTRICAL CHARACTERISTICS VIN = 3.7V, TA = +25C, unless otherwise noted. Parameter Symbol Reference Voltage VREF Feedback Current IFB FB Voltage Condition 2.7V ≤ VIN ≤ 7V Min Typ Max Units 1.178 1.190 1.202 V 10 50 nA 0 20 mV VFB = 0V VFB PFET Switch On Resistance (5) RDSON_P Switch Leakage PFET Current Limit Maximum Duty Cycle Minimum On Time(5) Switching Frequency Soft-Start Time Output Voltage Discharge Current Under Voltage Lockout Threshold Rising Under Voltage Lockout Threshold Hysteresis EN Input Logic Low Voltage EN Input Logic High Voltage EN Hysteresis EN Input Current Supply Current (Shutdown) Supply Current (Quiescent) VIN=5V VEN = 0V, VIN = 6V VSW = 0V IDIS 0 1 70 DMAX Fs TSS-ON 300 1200 No load EN=0V,VOUT=-1V 1.6 85 100 1500 0.5 mΩ 0.1 1800 25 2.35 2.45 2.55 V mV 0.4 100 1.7 0 0 0.2 V V mV uA nA μA 200 250 μA 1.2 VEN=2V, VFB=-0.1V, REF pin float, no switching A % ns kHz ms mA 200 VEN=2V VEN=0V VEN=0V μA Over Voltage Threshold Over Voltage Threshold Hysteresis -6.5 V 300 mV Thermal Shutdown 160 C 15 C Thermal Hysteresis (6) Notes: 5) Guaranteed by Characterization Test 6) Guaranteed by design MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 3 MP1400 – NEGATIVE DCDC POWER CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS VIN = 5V, VOUT = -5V, L =4.7µH, COUT=3 x 22μF, TA = +25ºC, unless otherwise noted. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 4 MP1400 – NEGATIVE DCDC POWER CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 5V, VOUT = -5V, L =4.7µH, COUT=3 x 22μF, TA = +25ºC, unless otherwise noted. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 5 MP1400 – NEGATIVE DCDC POWER CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS Performance waveforms are tested on the evaluation board of the Design Example section. VIN = 5V, VOUT = -5V, L =4.7µH, COUT=3 x 22μF, TA = +25ºC, unless otherwise noted. VOUT 5V/div. VOUT 5V/div. VOUT 5V/div. VIN 5V/div. VSW 5V/div. VIN 5V/div. VIN 5V/div. VSW 5V/div. VSW 5V/div. IINDUCTOR 2A/div. IINDUCTOR 2A/div. VOUT 5V/div. VOUT 5V/div. VOUT 5V/div. VIN 5V/div. VSW 5V/div. VEN 2V/div. VSW 5V/div. VEN 2V/div. VSW 5V/div. IINDUCTOR 2A/div. IINDUCTOR 200mA/div. IINDUCTOR 2A/div. IINDUCTOR 2A/div. VOUT 5V/div. VOUT 5V/div. VOUT/AC 10mV/div. VEN 2V/div. VEN 2V/div. VSW 5V/div. VSW 5V/div. VSW 5V/div. IINDUCTOR 2A/div. IINDUCTOR 2A/div. MP1400 Rev.1.1 5/27/2015 IINDUCTOR 200mA/div. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 6 MP1400 – NEGATIVE DCDC POWER CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) Performance waveforms are tested on the evaluation board of the Design Example section. VIN = 5V, VOUT = -5V, L =4.7µH, COUT=3 x 22μF, TA = +25ºC, unless otherwise noted. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 7 MP1400 – NEGATIVE DCDC POWER CONVERTER PIN FUNCTIONS Pin # Name A1 REF A2 FB B1 EN B2 VOUT C1, C2 GND D1 SW D2 IN MP1400 Rev.1.1 5/27/2015 Description Internal 1.19V reference voltage. Feedback pin. An external resistor divider from the output to GND, tapped to the FB pin, sets the output voltage. On/Off Control. Output Voltage power rail and input sense pin for output voltage. Connect load to this pin. Output capacitor is needed to decrease the output voltage ripple. Analog Ground Pin. Output Switching Node. SW is the drain of the internal high-side P-Channel MOSFET. Connect the inductor to SW to complete the converter. Supply Voltage. The MP1400 operates from a +2.7V to +7V unregulated input. Decouple capacitor is needed to prevent large voltage spikes from appearing at the input. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 8 MP1400 – NEGATIVE DCDC POWER CONVERTER FUNCTIONAL BLOCK DIAGRAM EN REF IN UVLO Current Sense 1.19V UVLO & Bandgap RSEN INTERNAL SS MAIN SWITCH PCH Current Limit COMP 1.5MHz OSCILLATOR EA Slope Comp COMP S CONTROL LOGIC SW PWM Over Voltage Protection VOUT FB Output Discharge GND Figure 1: Functional Block Diagram MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 9 MP1400 – NEGATIVE DCDC POWER CONVERTER OPERATION The MP1400 is a monolithic negative DCDC power converter with built-in internal power MOSFET. The DC-DC IC has a tiny surface mount 0.8mm x 1.6mm 8-ball CSP package and is optimized for low voltage powered applications where small size are critical. It achieves up to 600mA peak output current from a 2.7V to 7V input voltage. The output voltage can be regulated from -0.9V to -6V. The built-in 300m Ω PFET can provide high efficiency and eliminates an external boost capacitor. The duty cycle D of negative converter is defined as: D TON fOSC 100% VOUT 100% VIN VOUT Where TON is the main switch on time, fOSC is the oscillator frequency (1.5MHz), VOUT is the output voltage and VIN is the input voltage. Current Mode PWM Control Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limit for superior load and line response and protection of the internal main switch and rectifier diode. The MP1400 switches at a constant frequency (1.5MHz) and regulates the output voltage. During each cycle the PWM comparator modulates the power transferred to the load by changing the inductor peak current based on the feedback error voltage. During normal operation, the main switch is turned on for a certain time to ramp the inductor current at each rising edge of the internal oscillator, and switched off when the peak inductor current is above the error voltage. When the main switch is off, the rectifier diode will supply the current on immediately. Light Load Operation In light load condition, the load requires less energy so the charged current to inductor is smaller than heavy load. The rectifier diode discharges the inductor current. If the inductor current hit the zero, MP1400 will works in discontinuous conduction mode (DCM) operation. MP1400 Rev.1.1 5/27/2015 Startup and Shutdown When input voltage is greater than the undervoltage lockout threshold (UVLO), typically 2.5V, MP1400 can be enabled by pulling EN pin to higher than 1.2V. Leaving EN pin float or pull down to ground will disable MP1400. There is an internal 1Meg Ohm resistor from EN pin to ground. When the device is disabled, the part goes into output discharge mode automatically and its internal discharge MOSFET provides a resistive discharge path for the output capacitor. For the load capability is depending on the input voltage to output voltage ratio. It’s strongly recommending to power on VIN quick enough when load is high. Soft Start MP1400 has built-in soft start that ramps up the output voltage in a controlled slew rate. During power up, internal soft-start circuitry will limit the amount of in-rush current that drawn from the power supply. The soft start time is about 0.5ms typical. Current Limit MP1400 has a typical 1.6A current limit for the main PFET switch. When the PFET hits current limit, MP1400 will touch the hiccup threshold until the current lower down. This will prevent inductor current from continuing to build up which will result in damage of the components. Output Over Voltage Protection MP1400 has a built-in output voltage protection block. If the output voltage is lower than -6.5V, the PFET will be turned off immediately. After the output voltage status is removed, the part will reswitches automatically. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 10 MP1400 – NEGATIVE DCDC POWER CONVERTER Short Circuit Protection MP1400 enters short circuit protection mode when the current limit is hit, and tries to recover from short circuit with hiccup mode. In short circuit protection, MP1400 will disable output power stage, discharge soft-start cap and then automatically try to soft-start again. If the short circuit condition still holds after soft-start ends, MP1400 repeats this operation cycle till short circuit disappears and output rises back to regulation level. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 11 MP1400 – NEGATIVE DCDC POWER CONVERTER APPLICATION INFORMATION COMPONENT SELECTION Setting the Output Voltage The external resistor divider is used to set the output voltage (see Typical Application on page 1). The voltage on R1 is 1.19V. There is a REF current on R1 which is decided by R1’s resistance. The recommended REF current should be 10μA and R1 resistance should be 120k. Don’t set the REF current larger than 70μA. R2 is then given by: VOUT R1 1.19 R2 The feedback circuit is shown as Figure 2. VOUT VOUT R2 FB MP1400 R1 REF Choose inductor ripple current to be approximately 30% to 80% of the inductor current. The inductor current is: IL VIN VOUT IOUT VIN Then the peak inductor current at CCM is: IPeak IL 1 IL 2 High-frequency ferrite-core inductor materials reduce frequency-dependent power losses and improve efficiency compared to cheaper powdered-iron cores. The inductor should have low DCR (inductor series resistance without saturated windings) to reduce the resistive power loss; further reducing the DCR will significantly improve efficiency when DCR<<RDS-ON. Select a large-enough saturation current (ISAT) to support the current peak. Selecting the Input Capacitor Figure 2: Feedback Network VOUT (V) R1 (kΩ) R2 (kΩ) Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. It follows the ceramic capacitors are also a good choice for input decoupling and should be located as close as possible to the device. At least a ceramic capacitor larger than 10uF is recommended to put close to the IC. -1.8 -2.5 -3.3 -5 24.9(1%) 37.4(1%) Setting the Output Capacitor 24.9(1%) 52.3(1%) 24.9(1%) 69.8(1%) 24.9(1%) 105(1%) The output capacitor (COUT) is required to maintain the DC output voltage. The output capacitor requires a minimum capacitance value of 22μF at the programmed output voltage to ensure stability over the full operating range. A higher capacitance value may be required to lower the output ripple and also the transient response. Low ESR capacitors, such as X5R- or X7R-type ceramic capacitors, are recommended. Assuming that the ESR is zero, estimate the minimum output capacitance to support the ripple in the PWM mode as Table 1 lists the recommended resistors value for common output voltages. Table 1—Resistor Selection for Common Output Voltages Selecting the Inductor A 1µH to 10µH inductor is recommended for most applications. For highest efficiency, the inductor DC resistance should be small enough. For most designs, the inductance value can be derived from the following equation. L1 VIN VOUT IL VOUT VIN fOSC Where ΔIL is the inductor ripple current. COUT IOUT VOUT fOSC VOUT VOUT VIN fOSC is switching frequency. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 12 MP1400 – NEGATIVE DCDC POWER CONVERTER Additional output capacitance may also be required to reduce ripple in DCM mode and to ensure stability in PWM mode, especially at higher output load current. R4 R3 R2 U1 D1 L1 C2A C1A C2B C2C Conduction Loss (Cond) Dead time (DT) SW C1B Power Dissipation IC power dissipation plays an important role in circuit design—not only because of efficiency concerns, but also because of the chip’s thermal requirements. Several parameters influence power dissipation, such as: R1 GND VOUT VIN GND Switching Loss (SW) MOSFET Driver Current (DR) Based on these parameters, we can estimate the power loss to equal: PLOSS PCond PDT PSW PDR PS VOUT Supply Current (S) VIN PCB Layout Layout is important, especially for switching power supplies with high switching frequencies; poor layout results in reduced performance, EMI problems, resistive loss, and even system instability. Following the rules below can help ensure a stable layout design: 1. Connect the GND pin to the large ground plane by point connect mode. 2. Put the input capacitor as close as possible to the VIN pin while keep the GND end of the output capacitor close to the GND end of the input capacitor. 3. Put the cathode of the schottky close to the SW pin and the anode of the schottky close to the output capacitor to minimize parasitic inductance. 4. Route SW away from sensitive analog areas such as FB. It’s not recommended to route SW trace under chip’s bottom side. Design Example Below is a design example following the application guidelines for the specifications: Table 2: Design Example VIN VOUT Io 5V -5V 0.6A The detailed application schematic is shown in Figure 3. The typical performance and circuit waveforms have been shown in the Typical Performance Characteristics section. For more device applications, please refer to the related Evaluation Board Datasheets. Notes: 7) The recommended layout is based on the Figure 3 Typical Application circuit on the next page. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 13 MP1400 – NEGATIVE DCDC POWER CONVERTER TYPICAL APPLICATION CIRCUITS L1 4.7uH VIN C1B NS GND GND C1A 10uF 16V IN SW MP1400 100K EN D1 MBR230 R3 C2A 22uF 16V C2B 22uF 16V C2C 22uF 16V VOUT EN GND VOUT R4 10 FB GND REF R1 105K R2 24.9K GND Figure 3: 5VIN, -5V/0.6A Output MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 14 MP1400 – NEGATIVE DCDC POWER CONVERTER PACKAGE INFORMATION CSP (0.8mm X 1.6mm) PIN 1 ID PIN 1 ID MARKING PIN 1 ID INDEX AREA BOTTOM VIEW TOP VIEW SIDE VIEW NOTE: 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) BALL COPLANARITY SHALL BE 0.05 MILLIMETER MAX. 3) JEDEC REFERENCE IS MO-211, VARIATION BC. 4) DRAWING IS NOT TO SCALE. RECOMMENDED LAND PATTERN 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. MP1400 Rev.1.1 5/27/2015 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2015 MPS. All Rights Reserved. 15