SPDC12L00010

SPDC12L00010 10 A DC/DC converter module Preliminary Data Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ MTBF 1 000 000 (TA = 25 °C) 10 A max output current Input voltage range from 1.8 V to 14 V Supply voltage range from 4.5 V to 14 V Fixed or adjustable output voltage down to 0.6 V Fixed frequency voltage mode control Adjustable switching frequency Soft-start and inhibit Selectable UVLO threshold (5 V or 12 V bus) Master/slave synchronization with 180° phase shift Pre-bias start-up capability Selectable source/sink or source only capability after soft-start Power Good output with programmable delay Over voltage protection with selectable latched/not-latched mode Thermal shut-down Operating temperature range -40 °C ÷ 85 °C Applications ■ ■ ■ ■ ■ ■ ■ ■ ■ Laptop Blade servers RAID systems Network routers Cellular base stations Industrial equipment Test instrumentation Medical diagnostic equipment Points of load regulation Table 1. Device summary Output voltage [V] 0.6 ÷ 5 Input voltage [V] 1.8 ÷ 14 Output ripple [mVpp] 40 Efficiency [%] 70 ÷ 93 Notes Progr. output voltage Order code SPDC12L00010 October 2008 Rev 1 1/24 www.st.com 24 This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice. Contents SPDC12L00010 Contents 1 2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 2.2 Pin connection and mechanical data (dimensions in mm) . . . . . . . . . . . . . 5 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 3.2 3.3 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Thermal de-rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 Input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Auxiliary voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Inhibit function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Soft-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Multiple units synchronization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Power good signal and power good delay . . . . . . . . . . . . . . . . . . . . . . . . 14 Oscillator setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Current sink-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Under voltage lock out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Program setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Voltage sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Output voltage programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Additional loop compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Output over voltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Current limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Thermal shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Signal ground and power ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Input capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2/24 SPDC12L00010 Contents 5.19 5.20 Output capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Phase connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.1 6.2 Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 PCB footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3/24 Description SPDC12L00010 1 Description The ST SPDC12L00010 high density 10 A DC-DC converter is a complete step-down power supply. A single LGA package includes ST switching controller, power FETs, inductor and all the support components. SPDC12L00010 operates over a wide input voltage range of 1.8 V to 14 V, supporting an output range of 0.6 V to 5 V. High level of integration and synchronous rectification allows the SPDC12l00010 to deliver up to 10 A continuous current at up to 93% efficiency, without external heat sink or airflow. The device is a complete stand alone surface mount power supply, that can be handled and assembled like a standard integrated circuit. Moreover its low profile design permits the SPDC12L00010 to be soldered onto the back side of a printed circuit board, freeing up valuable board space. SPDC12L00010 is self protected against over voltage and short circuit conditions. A built in adjustable soft-start and inhibit guarantee correct functionality whatever the load is. Pre-bias start up capability is in place as well Power Good output with programmable delay to avoid false signals. The device is packaged in a thermally enhanced, compact (15 x 15 mm) and low profile (3 mm) over molded land grid array (LGA) package, suitable for automated assembly by standard surface mount equipment. The SPDC12L00010 is Pb-Free and RoHS compliant. 4/24 SPDC12L00010 Pin settings 2 2.1 Pin settings Pin connection and mechanical data (dimensions in mm) Figure 1. Pin connection AM00542v1 2.2 Pin description Table 2. Pin description Description Auxiliary voltage. Internally regulated 5 V voltage. It is used to supply the internal drivers and the voltage reference. Oscillator set. Connecting a resistor from this pin to SGND or to VAUX, the switching frequency can be increased or decreased. In OVP status the pin is pulled to 4.5 V (latched mode only). Voltage sense. Using this pin it is possible to recover the voltage drop on Vout track. VCC. Controller voltage supply pin. The operative voltage range for the internal controller is 4.5 V to 14 V Name Function J11 VAUX K11 OS L2 VSENSE L3 VCC 5/24 Pin settings Table 2. Pin description (continued) Description SPDC12L00010 Name Function L4 PG Power Good. This pin is an open collector output, with a 10 kΩ pull-up resistor connected to VAUX. It is pulled low if the output voltage is not within specified thresholds (90%-110%). Power Good delay. A capacitor connected between this pin and SGND, introduce a delay between the internal PG comparator and the external signal rising edge. No delay can be introduced on the falling edge of PG signal. Synchronization. This is the master/slave pin. Two or more devices can be synchronized connecting the SYNC pins together. Program. This pin allows following settings: - Enable/disable the current sink mode capability after soft-start; - Enable/disable the OVP latch mode; - Setting UVLO threshold for 5 V or 12 V bus. Signal ground. All references are referred to these pins, internally connected to PGND. Feed-back. This pin is connected to the error amplifier inverting input. Compensation. This pin is connected to the error amplifier output. Soft-start_inhibit low The soft-start time is programmed connecting an external capacitor from this pin to SGND; This pin can be used to inhibit the module. DC input voltage. See Section 5.18 on page 18 for mandatory condition. Return for input/output voltage source. Regulated power output. See Section 5.19 on page 18 for mandatory condition. Phase This pins area is foreseen for module power losses dissipation; see Section 5.20 on page 19 for details. L5 PGDLY L6 SYNC L7 PRG L8 L9 L10 SGND FB COMP L11 SS_INL Bank 1 Bank 2 Bank 3 VIN PGND VOUT Bank 4 PH 6/24 SPDC12L00010 Maximum ratings 3 3.1 Maximum ratings Absolute maximum ratings Table 3. Symbol VK11 VL2 VL3 VL4 VL5 VL6 VL7 VL9 VL10 VL11 Vi Vo Io Absolute maximum ratings Parameter OS to SGND and PGND VSENSE to SGND and PGND VCC to SGND and PGND PG to SGND and PGND PGDLY to SGND and PGND SYNC to SGND and PGND PRG to SGND and PGND FB to SGND and PGND COMP to SGNG and PGND SS_INL to SGND and PGND VIN to SGND and PGND VOUT to SGND and PGND Maximum output current Value -0.3 to 6 -0.3 to 18 -0.3 to 18 -0.3 to 18 -0.3 to 6 -0.3 to 6 -0.3 to 6 -0.3 to 6 -0.3 to 6 -0.3 to 6 -0.3 to 18 -0.3 to 18 Int. limited Unit V V V V V V V V V V V V A 3.2 Thermal data Table 4. Symbol TSTG TOP Table 3. Thermal data Parameter Storage temperature range Operating temperature range Value -40 ÷ 105 -40 ÷ 85 Unit °C °C 7/24 Maximum ratings SPDC12L00010 3.3 Thermal de-rating The thermal de-rating is obtained reducing the maximum output current, to limit the module temperature to the maximum allowable value. Since a lot of parameters affect the module power dissipation, the best way to get a precise thermal de-rating is to measure the module temperature in the final application condition. For this purpose, the case top side must be monitored at the central point T1 (see Figure 2); the maximum temperature allowable value at T1 is 125 °C. Figure 2. Measurement points for thermal de-rating (top side) AM00543v1 All data reported in the following tables are valid for free air condition and module placed on 25 cm2, 4 layers, 1.6 mm FR4 printed circuit board. Table 5. Symbol Thermal de-rating for Vout = 5.0 V Parameter Test condition VIN = 8 V TA = 75 °C Value TBD TBD TBD TBD TBD A TBD TBD TBD TBD TBD A TBD TBD TBD A Unit Io Output current VIN = 8 V TA = 80 °C VIN = 8 V TA = 85 °C VIN = 10 V TA = 70 °C Io Output current VIN = 10 V TA = 75 °C VIN = 10 V TA = 80 °C VIN = 10 V TA = 85 °C VIN = 12 V TA = 60 °C VIN = 12 V TA = 65 °C Io Output current VIN = 12 V TA = 70 °C VIN = 12 V TA = 75 °C VIN = 12 V TA = 80 °C VIN = 12 V TA = 85 °C 8/24 SPDC12L00010 Table 5. Symbol Maximum ratings Thermal de-rating for Vout = 5.0 V (continued) Parameter Test condition VIN = 14 V TA = 50 °C VIN = 14 V TA = 55 °C VIN = 14 V TA = 60 °C Io Output current VIN = 14 V TA = 65 °C VIN = 14 V TA = 70 °C VIN = 14 V TA = 75 °C VIN = 14 V TA = 80 °C VIN = 14 V TA = 85 °C Value TBD TBD TBD TBD A TBD TBD TBD TBD Unit Table 6. Symbol Io Thermal de-rating for Vout = 3.3 V Parameter Output current Test condition VIN = 8 V TA = 80 °C VIN = 8 V TA = 85 °C VIN = 10 V TA = 75 °C Value TBD A TBD TBD TBD TBD TBD TBD A TBD TBD TBD TBD TBD TBD TBD A A Unit Io Output current VIN = 10 V TA = 80 °C VIN = 10 V TA = 85 °C VIN = 12 V TA = 70 °C Io Output current VIN = 12 V TA = 75 °C VIN = 12 V TA = 80 °C VIN = 12 V TA = 85 °C VIN = 14 V TA = 65 °C VIN = 14 V TA = 70 °C Io Output current VIN = 14 V TA = 75 °C VIN = 14 V TA = 80 °C VIN = 14 V TA = 85 °C 9/24 Maximum ratings SPDC12L00010 Table 7. Symbol Io Thermal de-rating for Vout = 2.5 V Parameter Output current Test condition VIN = 10 V TA = 80 °C VIN = 10 V TA = 85 °C VIN = 12 V TA = 75 °C Value TBD A TBD TBD TBD TBD TBD TBD A TBD TBD A Unit Io Output current VIN = 12 V TA = 80 °C VIN = 12 V TA = 85 °C VIN = 14 V TA = 70 °C Io Output current VIN = 14 V TA = 75 °C VIN = 14 V TA = 80 °C VIN = 14 V TA = 85 °C Table 8. Symbol Io Thermal de-rating for Vout = 1.8 V Parameter Output current Test condition VIN = 10 V TA = 80 °C VIN = 10 V TA = 85 °C Output current VIN = 12 V TA = 80 °C VIN = 12 V TA = 85 °C Output current VIN = 14 V TA = 80 °C VIN = 14 V TA = 85 °C Value TBD A TBD TBD A TBD TBD A TBD Unit Io Io Table 9. Symbol Io Thermal de-rating for Vout = 1.2 V Parameter Output current Test condition VIN = 14 V TA = 80 °C VIN = 14 V TA = 85 °C Value TBD A TBD Unit 10/24 SPDC12L00010 Electrical characteristics 4 Table 10. Symbol Electrical characteristics Electrical characteristics Parameter Test condition VIN = 12 V, Io = 10 A, Co = 2x330 μF BW = 20 MHz VIN = 1.8 ÷ 14 V VIN = 1.8 ÷ 14 V VCC = 12 V, Io = 0 A VSS_INL < 0.5 V VCC = 12 V, Io = 0 A, OS = open, VSS_INL > 0.5 V VCC = 12 V, Io = 0 A, OS = open, VSS_INL < 0.5 V VCC = 12 V, Io = 10 A, TA = 0 ÷ 85 °C TA = -40 ÷ 85 °C VCC = 5.5 ÷ 14 V, IAUX = 1 ÷ 100 mA Device OFF VSS_INL = 2 V VSS_INL = 0 ÷ 0.5 V Power Good voltage low Power Good high threshold (VFB/0.6) Power Good low threshold (VFB/0.6) Overvoltage high threshold (VFB/0.6) Overvoltage low threshold (VFB/0.6) VCC turn-on threshold IPG = -5 mA VFB rising VFB falling VFB rising VFB falling 5 V BUS, VIN > 1.7 V 12 V BUS, VIN > 1.7 V 5 V BUS, VIN > 1.7 V 12 V BUS, VIN > 1.7 V VIN rising VIN falling 4.0 8.3 3.6 7.4 1.1 0.9 108 88 7 20 10 30 0.5 110 90 120 117 4.2 8.6 3.8 7.7 1.25 1.05 4.4 V 8.9 4.0 V 8.0 1.47 1.27 V V 112 92 678 0.593 4.5 0 12 65 5 35 5 729 0.6 5 780 0.605 5.5 0.5 13 45 V % % % % Min Typ Max Unit Vr Io Iol Iq Iqst-by ICCq Ripple voltage Output current Current limit Total quiescent current Total stand-by quiescent current VCC quiescent current 40 10 mVpp A A mA mA mA mA kHz V V V μA ICCqst-by VCC stand-by quiescent current fs VFB VAUX Switching frequency Feedback voltage (Reference voltage) Auxiliary voltage VSS_INL Inhibit threshold ISS_INL VPG VPGhth VPGlth VOVhth VOVlth VCConth Soft-start current VCCoffth VINhth VINlth VCC turn-off threshold VIN high threshold VIN low threshold 11/24 Application information SPDC12L00010 5 5.1 Application information Input voltage There are two voltage supply pins: VCC (pin L3), for controller voltage supply; VIN (bank 1), for power circuit voltage supply. VCC and VIN can be connected and supplied together; if VIN is lower than 4.5 V, VCC must be supplied separately. The recommended maximum operating DC input voltage is 14 V. 5.2 Auxiliary voltage VAUX (pin J11) pin must be used to supply PRG and OS setting resistors. No capacitor is required. 5.3 Inhibit function SS_INL (pin L11) allows putting the device in stand-by mode. With SS_INL lower than 0.5 V, the device is disabled and the current consumption is reduced to 5 mA, for VIN = 12 V. With SS_INL higher than 0.5 V the device is enabled. Since SS_INL has soft-start function, it is mandatory to implement the inhibit function using an open collector device (i.e. small signal transistor), to not influence the module behavior (see Figure 3). Figure 3. Inhibit function AM00544v1 12/24 SPDC12L00010 Application information 5.4 Soft-start The soft-start phase begins when both VCC and VIN raise above their turn-on thresholds, otherwise the SS_INL pin is internally shorted to SGND. A ramp is generated at SS_INL pin during start-up, charging the external capacitor CSS with an internal current generator. The initial value for this current is 30 μA and it charges the capacitor up to 0.5 V, after that, it is reduced to 10 μA until the final charge value approximately 4 V. In the meanwhile, the controller internal voltage reference raises to its final value, following the SS_INL pin voltage slope. During soft-start, the module provides a constant current protection, limiting the output current at the maximum value, without entering in HICCUP mode. If there is not current limitation, the output voltage slope follows the SS_INL pin slope. The output voltage rise time, can be set choosing proper CSS value. The soft-start phase ends when the SS_INL pin voltage reaches 3.5 V. A capacitor CSS = 3 3 nF is present on the module, to perform a minimum soft-start time, suitable for Co = 10000 μF max. output capacitor; in this condition and with 10 A output current resistor load, the output voltage rise time is around 5ms, but the complete soft-start time is around 10ms. Using the minimum output capacitor Co = 660 μF and with 10 A resistor load, the output voltage rise time is around 2 ms. 5.5 Multiple units synchronization Using more than one unit on the same circuit, it is possible to synchronize the switching frequency oscillators, connecting all SYNC (pin L6) together. The device with the higher switching frequency will be the Master, while the other will be the Slaves. The best way to synchronize two or more devices is to set same switching frequency, in any case, the switching frequencies can differ for a maximum of 50% of the lowest one. Using and external clock signal, to synchronize one or more devices working at a different switching frequency, it is recommended to follow the below formula: fsw ≤ fext ≤ 1.3fsw The phase shift between master and slaves is approximately 180°. 13/24 Application information SPDC12L00010 5.6 Power Good signal and Power Good delay The output voltage is monitored by FB (pin L9), if it is not within ± 10% (typ.) of the programmed value, the PG (pin L4) output is forced low. The PG signal can be delayed by adding an external capacitor on PGDLY (pin L5), the delay can be calculated with the following formula: PGdelay = 0.5 x CPGDLY(pF) [μs] 5.7 Oscillator setting The switching frequency is internally fixed to 729 kHz, this value can be slightly varied using an external resistor ROS connected between OS (pin K11) and SGND (L8) or VAUX (pin J11). Since the OS pin is maintained at fixed voltage (typ. 1.2), the frequency is increased/decreased proportionally to the current sunk/sourced from/into the pin. In particular, connecting ROS to SGND the frequency is increased according the following formula: fSW = 729 + (9.88x106/ROS) [kHz] Connecting ROS to VAUX the frequency is reduced according to the following formula: fSW = 729 - (30.1x106/ROS) [kHz] 5.8 Current sink-mode Connecting a proper resistor (see par. Section 5.10 on page 15) from PRG (pin L7) to VAUX (pin J11), it is possible to select the sink-mode operation, that means to allow the output current to reverse its polarity into the converter output inductor. If the sink-mode is enabled, the converter can sink current from the load after soft-start; If the sink-mode is disabled, the converter never sinks current. Note: When output low current operation is required (Iout < 2 A), sink-mode operation is recommended, this condition improves output voltage transient response and reduces output voltage ripple. 14/24 SPDC12L00010 Application information 5.9 Under voltage lock out Connecting a proper resistor (see par. Section 5.10) from PRG (pin L7) to VAUX (pin J11), it is possible to select two different thresholds for UVLO: 4.2 V/3.8 V for 5 V input range; 8.6 V/7.7 V for 12 V input range. 5.10 Program setting Connecting a resistor from PRG (pin L7) to VAUX (pin J11), it is possible to select different operation modes, according to the following table: Table 11. RPRG n.c. 11 kΩ 6.2 kΩ 4.3 kΩ 2.7 kΩ 1.8 kΩ 1.2 kΩ 0Ω 12 V range Latched Latched Not Yes 5 V range Latched Latched Not latched Not latched Not Yes Not Yes Program setting UVLO. OVP Not latched Not latched Sink-mode Not Yes 5.11 Voltage sensing Using VSENSE (pin L2) it is possible to recover the voltage drop on VOUT PCB track. Connect VSENSE in a point closed to the load (see Figure 4). Using VSENSE connection, it will not recover the voltage drop on PGND PCB track. Leaving VSENSE floating, the output voltage will be sensed at VOUT (bank 3). Figure 4. Voltage sensing 15/24 Application information SPDC12L00010 5.12 Output voltage programming Adding a resistor Rx between FB (pin L9) and SGND (L8) or between FB and VSENSE (pin L2), it is possible to change the output voltage. Connecting the resistor to SGND the output voltage increase (see Figure 5 a); Connecting the resistor to VSENSE the output voltage decrease (see Figure 5 b). Calculate the resistor for increasing output voltage with the following formula: Rx = 0.6 / (VOUT – 1.2) [kΩ] valid for VOUT > 1.2 V Calculate the resistor for decreasing output voltage with the following formula: Rx = (VOUT – 0.6) / (1.2 – VOUT) [kΩ] valid for 0.6 < VOUT < 1.2 V The module output voltage is 1.2 V with Rx = n.c. Figure 5. Output voltage programming 5.13 Additional loop compensation If required by particular load condition, it is possible to change the feedback loop compensation, adding a pole with an external R-C network between FB (pin L9) and COMP (pin L10) (see Figure 6 a), or adding a zero with an external R-C network between FB and VSENSE (pin L2) (see Figure 6 b). Figure 6. Additional loop compensation 16/24 SPDC12L00010 Application information 5.14 Output over voltage protection The device provides OVP: when the voltage sensed on FB (pin L9) reaches a value greater than 20% of reference, the on module low side driver is turned ON and the converter stop switching operation. If the OVP not latched mode has been set, the on module low side MOSFET is kept ON, as long as the over voltage condition is detected. If OVP latched mode has been set, the low side MOSFET is turned ON and the OS (pin K11) is forced high (4.5 V typ.), until VCC is toggled. It must be taken in account that there is an electrical network between the output terminal and FB, therefore the voltage at this pin is not a perfect replica of output voltage. If the converter is set to sink current, the low side MOSFET could be turned ON before the output voltage exceeds the over voltage threshold (109% typ.), because the error amplifier will change its balance in advance. If the sink-mode is disabled, the low side MOSFET will be turned ON only when the OVP operate, in this case a delay between the output voltage rising and the FB rising can appear and the OVP can operate late (126% typ.). 5.15 Current limitation The device realizes the over current protection sensing the current on board high side MOSFET and on board low side MOSFET, therefore two current limits are set: peak current limit and valley current limit. The peak current protection is active when the high side MOSFET is turned ON, the valley current protection is enabled when the low side MOSFET is turned ON. After soft-start is completed, if an over current occurs, the device enters in HICCUP mode: both high side and low MOSFETs are turned OFF; the soft-start capacitor is discharged with a 10 μA constant current; when the voltage on SS_INL (pin L11) reaches 0.5 V the soft-start phase restart. During the soft-start phase the OCP provides a constant current protection. 5.16 Thermal shutdown When the controller junction temperature reaches 150 ± 10 °C, the device shutdown. Both MOSFET are turned OFF and the soft-start capacitor is discharged. The device does not restart until the junction temperature goes down to 120 °C and until the voltage on the soft-start capacitor reaches 0.5 V. 17/24 Application information SPDC12L00010 5.17 Signal ground and power ground SGND (L8) and PGND (bank 2) are connected together on the module. Connect to SGND the capacitor for PGDLY and SS_INL, the resistor for FB and OS. Connect to PGND the return for SS_INL. It is important to not create a ground loop between SGND, PGND and other GND present on the application circuit (see Figure 7). Figure 7. Signal ground and power ground 5.18 Input capacitors The input capacitor present on the module is not able to sustain the input RMS current. Connect 2 x 2.2 μF 16 V X7R ceramic capacitor (Cin) closed to the input pins VIN and PGND (bank 1 and bank 2), to satisfy minimum functional requirement. Connect proper low impedance capacitors to reduce the input ripple current, according to the application requirement. 5.19 Output capacitors The output capacitors present on the module are able to sustain output RMS current. Connect 2 x 330 μF POSCAP SANYO capacitor (Co) or equivalent, closed to the output pins VOUT and PGND (bank 3 and bank 2), to guarantee output voltage stability and specified voltage ripple. 18/24 SPDC12L00010 Application information 5.20 Phase connection On the module bottom, there is an area relative to PH (bank 4) connection: this area is internally connected to the high side MOSFET source and to the low side MOSFET drain; this electrical point is used to dissipate heat generated by the two MOSFETs. Connect PH (bank 4), to an insulated copper area on the mother board, to ensure proper heat sink. Since the PH signal contains very fast voltage transients, it is recommended to take in account possible inducted noise on mother board, i.e.: it is advised against to lead under the module printed circuit board tracks with susceptible signals. 19/24 Package mechanical data SPDC12L00010 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com Figure 8. Package mechanical data AM00542v1 20/24 SPDC12L00010 Package mechanical data 6.1 Soldering Soldering phase has to be execute with care: in order to avoid undesired melting phenomenon, particular attention has to be take on the set up of the peak temperature. Here following some suggestions for the temperature profile based on IPC/JEDEC J-STD-020C, July 2004 recommendations. Table 12. Soldering Profile feature Average ramp up rate (TSMAX to TP) Preheat Temperature min (TS min) Temperature max (TS max) Time (tS min to tS max) (tS) Time maintained above: Temperature TL Time tL Peak temperature (Tp) Time within 5 °C of actual peak temperature (tP) Ramp down rate Time from 25 °C to peak temperature PB free assembly 3 °C / sec max 150 °C 200 °C 60 – 100 sec 217 °C 40 – 70 sec 240 + 0 °C 10 – 20 sec 6 °C / sec 8 minutes max Figure 9. Soldering 21/24 Package mechanical data SPDC12L00010 6.2 PCB footprint Use Figure 10 as suggested PCB footprint. Figure 10. PCB footprint for SPDC12L00010 (dimensions in mm) 22/24 SPDC12L00010 Revision history 7 Revision history Table 13. Date 17-Oct-2008 Document revision history Revision 1 First release Changes 23/24 SPDC12L00010 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. 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