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CALIFORNIA MICRO DEVICES
CMPWR280
Pin Diagram
1.5A SmartORTM Dual Regulator with VAUX Drive
Features Automatic selection of VCC or VSBY Drive control signal for external VAUX switch Continuous 3.3V output supply Glitch-free output during supply transitions Built-in hysteresis for supply selection VCC regulates up to 1.5A output current VSBY regulates up to 375mA output current Foldback current limiting Thermal shutdown with hysteresis On-chip controller operates from VCC, VSBY or VOUT Applications Peripheral Component Interface (PCI) Adapter Cards Network Interface Cards (NICs) Multiple Powered Systems Systems with Standby Capabilities Product Description The California Micro Devices SmartORTM CMPWR280 is a fully protected Dual-Input low dropout CMOS regulator that also provides the necessary control signal for driving an external auxiliary Pchannel MOSFET switch. The SmartORTM device automatically selects one of three possible inputs on a priority basis: VCC (1.5A), VSBY (375mA) or VAUX via the drive signal used to control an external switch. VCC is given first priority. In the event of the VCC supply being powered down, the device will automatically deselect the VCC prior to regulator dropout and immediately select VSBY (second priority) as its power source. If neither VCC nor VSBY are present the drive control output will turn-on an external P-channel MOSFET switch from an auxiliary 3.3V supply VAUX to VOUT. All the necessary control circuitry needed to provide a smooth and automatic transition between all three supplies has been incorporated. This allows VCC to be dynamically switched without loss of output voltage. The CMPWR280 is internally protected against output short-circuits, current overload and thermal overload.
Typical Application Circuit
Simplified Electrical Schematic
Pins
5
STANDARD PART ORDE RING INFORMATION Package Ordering Part Number Style Part Marking
TO263 CMPWR280TO
When placing an order please specify desired shipping: Tubes or Tape & Reel.
(c) 2000 Calirornia Micro Devices Corp. All rights reserved. CMPWR300 is a trademark of California Micro Devices Corp. 3/00
C0660200
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
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CALIFORNIA MICRO DEVICES
ABSOLUTE MAXIMUM RATINGS Parameter ESD Protection (HBM) V CC , V S BY , VOUT D rive Logic Voltage Storage Temperature Range Operating Ambient Operating Junction Power D issipation: (TO-263)
Note 1
CMPWR280
Unit V V V
oC
Rating 2000 +6.0, Gnd -0.5 V CC (V S BY ) +0.5, GND -0.5 -40 to +150 0 to +70 0 to +150 Internally Limited
W
OPERATING CONDITIONS Parameter V CC, V SBY Temperature (Ambient) Load Current C EXT Range 5.0 0.25 0 to +70 0 to 1500 10 10 % Unit V
oC
mA F
Symbol
V OUT V CCSEL V CCDES V CCHYST I OUT IS/C IRCC IRSBY VR LOAD VR LINE ICC ISBY IGND
ELECTRICAL OPERATING CHARACTERISTICS (over operating conditions unless specified other wise) Parameter Conditions MIN TYP R e g u l a t o r O u t p u t Vo l t a g e 0mA < ILOAD < 1500mA (VCC ) 3.135 3.30 0mA < ILOAD < 375mA (VSBY ) S e l e c t Vo l t a g e V CC R e g u l a to r E n a b l e d 4.50 V CC D e s e l e c t Vo l ta g e V CC R e g u l a to r D i s a b l e d 3.90 4.10 H y s t e r e s i s Vo l t a g e V CC H y s te re s i s : Note 2 0.40 M a x i mu m Ou t p u t C u r r e n t V CC s e l e c te d 150 0 2 50 0 V SBY s e l e c te d 375 7 50 S h o rt Ci rc u i t Ou tp u t Cu rre n t V CC s e l e c te d 800 V SBY s e l e c te d 200 VCC Pin Reverse Leakage VSBY Pin Reverse Leakage VCC Load Regulation VSBY Load Regulation Line Regulation VCC Supply Current VSBY Supply Current Ground Current: Note 3 V CC = 0 V. V SBY = 5 V V SBY = 0 V. V CC = 5 V VCC selected, ILOAD = 15mA to 1500mA V SBY selected, ILOAD = 5mA to 375mA VCC = 4.5V to 5.5V, ILOAD = 5mA V CC selected, IOUT = 0mA VCCDES > VCC > VAUX or VOUT V SBY selected, IOUT = 0mA Regulator D isabled (only VOUT present) Regulator selected, ILOAD = 5mA Regulator selected = 5V, ILOAD = 500mA R DS to V CC , V CC > V CCSEL R DS to G N D , V CCDES > V CC CDRIVE = 1 n F, V CC tRISE < 1 0 0 n s CDRIVE = 1 n F, V CC tFALL < 1 0 0 n s 10 10 30 30 5 1.5 0.1 1.5 0.2 1.5 1.8 5 0.5 5.0 0.5 16 5 30
MAX 3.465
UNIT
V
4.70 V mA mA 10 0 10 mV mV mA mA mA k s C A
ROH ROH tDH tDL TDISABLE THYST
D rive RDS High D rive RDS Low D rive High D elay D rive Low D elay Shutdown temperature Thermal hysteresis
3.0 0.2 3.0 0.3 3.0 3.5 10 1
(c)2000 California Micro Devices Corp. All rights reserved.
Note 1: The maximum power dissipation of this device is internally limited by thermal shutdown circuitry. To achieve a power dissipation of 3.0 watts, a case-to-ambient thermal resistance of 25C/W must be provided. This will typically require dedicated heatsinking ability of the printed circuit board. For more details, please see the Typical Thermal Characteristics section. Note 2: The hysteresis defines the maximum level of acceptable disturbance on VCC during switching. It is recommended that the VCC source impedance be kept below 0.15 to ensure the switching disturbance remains below the hysteresis during select/deselect transitions. Note 3: Ground pin current consists of controller current (0.2mA) and regulator current when selected
2
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Interface Signals VCC is the primary 5V power supply for the internal regulator. Whenever VCC exceeds VCCSEL (4.5V), the internal regulator (1500mA) will be enabled and deliver a fixed 3.3V at VOUT. When VCC falls below VCCDES (4.1V typically) the regulator will be disabled. Internal loading on this pin is typically 1.5mA when the regulator is enabled, which reduces to 0.2mA whenever the regulator is disabled. If VCC falls below either the VSBY or VOUT voltage, the loading on VCC will reduce to only a few microamperes. During a VCC power up sequence, there will be an effective step increase in VCC line current when the regulator is enabled. The amplitude of this step increase will depend on the dc load current and any current required for charging/ discharging the load capacitance. This line current transient will cause a voltage disturbance at the VCC pin proportional to the effective power supply source impedance being delivered to the VCC input. To prevent chatter during Select and Deselect transitions, a built-in hysteresis voltage of 400mV has been incorporated. It is recommended that the power supply connected to the VCC input should have a source impedance of less than 0.15 to minimize the chatter during the enabling/disabling of the regulator. VSBY is the standby 5V supply power source, which is only selected on when VCC < VCCDES. If VSBY is selected, the regulator can deliver a maximum of 375mA load current. Whenever VSBY exceeds both VCC and VOUT, it will be used to provide all the internal bias currents and any necessary regulator current.
Pin Functions Symbol VSBY VCC GN D VOUT D rive
CMPWR280
GND is the reference for all voltages. The current that flows in the ground connection is very low (typically 2.0mA) and has minimal variation over all load conditions VOUT is the regulator output voltage connection used to power the load. An output capacitor of ten microfarads is used to provide the necessary phase compensation, thereby preventing oscillation. This capacitor also helps to minimize the peak output disturbance during power supply changeover. When both VCC and VSBY fall below VOUT, VOUT will be used to provide the necessary quiescent current for the internal reference circuits. This ensures excellent start-up characteristics for the regulator. Drive is an active LOW logic output intended to be used as the control signal for driving an external P-channel MOSFET switch whenever the regulator is disabled. This will allow the voltage at VOUT to be powered from an auxiliary supply voltage (3.3V). The Drive pin is pulled HIGH to VCC whenever the regulator is enabled, thus ensuring that the auxiliary supply remains isolated during normal regulator operation.
D escription Standby Positive 5V Supply input. Used to power internal regulator (375mA) when VCC is not available. Main Positive 5V Supply input. Powers the internal regulator (1.5A) whenever VCC exceeds the select threshold (typically 4.5V) Ground Reference for all voltages. Regulator output voltage (3.3V). Logic signal for controlling external auxiliary switch. Active LOW output whenever the internal regulator is disabled.
(c) 2000 Calirornia Micro Devices Corp. All rights reserved. 3/00
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
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CALIFORNIA MICRO DEVICES
Typical DC Characteristics
CMPWR280
Unless stated otherwise, all DC characteristics were measured at room temperature with a nominal VCC supply voltage of 5.0 volts and an output capacitance of 10F.
Fig 1.1. Line Regulation
Vout [V]
Fig 1.1. VCC Line regulation is measured while forcing the deselect threshold to an artificial low level for loads of 100mA, 500mA and 1.5A. At the maximum rated load of 1.5A, a drop in line regulation occurs when the VCC supply voltage drops below 3.8V. For light load conditions (100mA), regulation is maintained as low as 3.2V.
3.35 3.30 3.25 3.20 3.15 3.10 3.05 3.3 3.6 3.9 4.2 4.5 4.8
100mA load
500mA load 1.5A load
Vcc [V]
Fig 1.2. Vcc Load Regulation (pulse condition)
Fig 1.2. VCC Load regulation (pulse condition) performance is shown up to and beyond the rated load. A change in load from 10% to 100% of rated current (150mA to 1500mA) results in an output voltage change of about 20mV. This translates into an effective output impedance of less than 15m.
Vout [V]
3.36 3.34 3.32 3.30 3.28 3.26 3.24 0 500 1000 1500
Load Current [mA]
Fig 1.3. Vsby Load Regul. (pulse condition)
Fig 1.3. VSBY Load regulation (pulse condition) performance is shown up to and beyond the rated load. A change in load from 10% to 100% of rated (50mA to 500mA) results in an output voltage change of about 20mV. This translates into an effective output impedance of less than 50m.
Vout [V]
3.36 3.34 3.32 3.30 3.28 3.26 3.24 0 100 200 300 400 500
(c)2000 California Micro Devices Corp. All rights reserved.
Load Current [mA]
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CALIFORNIA MICRO DEVICES
CMPWR280
Fig 1.4. Ground Current 3.0 2.5 I GND [mA] 2.0 1.5 1.0 0.5 0.0 0 500 1000 Load Current [mA] 1500
Fig 1.4. Ground Current is shown across the entire range of load conditions. The ground current of 2mA has minimal variation across the range of load conditions and shows only a slight increase at maximum load due to the current limit protection circuitry.
Fig 1.5. Vcc Supply Current (No Load)
Fig 1.5. Supply Current of the device is shown across the entire VCC range. The supply current remains below 0.2mA when the VCC supply is lower than 4.2V and the regulator is deselected. Above this point, the regulator is enabled and a supply current of 2.0mA is conducted.
10000
1000 I CC [A] 100 10 1 2 3 Vcc [V] 4 5
(c) 2000 Calirornia Micro Devices Corp. All rights reserved. 3/00
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
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CALIFORNIA MICRO DEVICES
Typical Transient Characteristics The transient characterization test setup shown below includes the effective source impedance of the VCC supply (RS). This was measured to be approximately 0.1. It is recommended that this effective source impedance be no greater than 0.15 to ensure precise switching is maintained during VCC selection and deselection. Both the rise and fall times during VCC power-up/down sequencing were controlled to be around 10 milliseconds duration. This is considered to represent worst case conditions for most application circuits.
CMPWR280
During a selection or deselection transition the DC load current is switching from VAUX to VCC and vice versa, or from VSBY to VCC. In addition to the normal load current there may also be an in-rush current for charging/discharging the load capacitor. The total current pulse being applied to either VAUX or VCC is equal to the sum of the dc load and the corresponding inrush current. Transient currents in excess of one amp can readily occur for brief intervals when either supply commences to power the load.
VCC Load Transient Response is shown for a step load from 15mA to 1500mA. An overshoot of approximately 300mV is observed, before settling within 3us. VCC Load Transient Response
VSBY Load Transient Response is shown for a step load from 5mA to 375mA. An overshoot of approximately 100mV is observed, before settling within 1us. VSBY Load Transient Response
(c)2000 California Micro Devices Corp. All rights reserved.
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Tel: (408) 263-3214
Fax: (408) 263-7846
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CALIFORNIA MICRO DEVICES
Fig 2.1 VCC cold start
CMPWR280
Fig 2.2 VCC full power down
Typical Transient Characteristics - Cold Start and Full Power Down
Fig 2.3 VSBY cold start
Fig 2.4 VSBY full power down
(c) 2000 Calirornia Micro Devices Corp. All rights reserved. 3/00
215 Topaz Street, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
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CALIFORNIA MICRO DEVICES
Typical Transient Characteristics - VCC Power Changeover
CMPWR280
Fig 2.8 VCC power down (VSBY = 5V)
Fig 2.7 VCC power up (VSBY = 5V)
Fig 2.9 VCC power up (VAUX = 3.3V)
Fig 2.10 VCC power down (VAUX = 3.3V)
Fig 2.11 VCC power up (VAUX = 3.0V)
Fig 2.12 VCC power down (VAUX = 3.0V)
(c)2000 California Micro Devices Corp. All rights reserved.
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Tel: (408) 263-3214
Fax: (408) 263-7846
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CALIFORNIA MICRO DEVICES
Typical Thermal Characteristics
CMPWR280
Based on a maximum power dissipation of 2.85W (1.9Vx1.5A) with an ambient of 70C the resulting junction temperature will be: TJUNC = TAMB + PJUNC (JA ) = 70C + 2.85W (25C/W) = 70C + 71C = 141C All thermal characteristics of the CMPWR280TO were measured using a double sided board with two square inches of copper area connected to the GND pins for heat spreading. Measurements showing performance up to junction temperature of 125C were performed under light load conditions (5mA). This allows the ambient temperature to be representative of the internal junction temperature. Note: The use of multi-layer board construction with power planes will further enhance the thermal performance of the package. In the event of no copper area being dedicated for heat spreading, a multi-layer board construction will typically provide the CMPWR280TO with an overall JA of 25C/W which allows up to 2.5W to be safely dissipated.
Thermal dissipation of junction heat consists primarily of two paths in series. The first path is the junction to the case (JC) thermal resistance which is defined by the package style, and the second path is the case to ambient (CA) thermal resistance, which is dependent on board layout. The overall junction to ambient (JA) thermal resistance is equal to: JA = JC + CA For a given package style and board layout, the operating junction temperature is a function of junction power dissipation PJUNC, and the ambient temperature, resulting in the following thermal equation: TJUNC = TAMB + PJUNC (JC ) + PJUNC (CA ) = TAMB + PJUNC (JA ) The CMPWR280TO is housed in a TO-263 5-lead package, which provides a JC of 3C/W. The ground tab is soldered down to the PCB. When the device is mounted on a double sided printed circuit board with two square inches of copper allocated for heat spreading, the resulting JA is 25C/W.
Fig 3.1. Output Voltage vs. Temperature
3.340
Fig 3.1. Output Voltage vs. Temperature. This shows the regulator VOUT performance up to the maximum rated junction temperature. The overall 125C variation in junction temperature causes an output voltage change of about 25mV.
3.320
Vout [V]
5mA load
3.300
3.280
3.260 0 25 50 75 100 125
Junction Temperature [ C]
(c) 2000 Calirornia Micro Devices Corp. All rights reserved. 3/00
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CALIFORNIA MICRO DEVICES
Typical Thermal Characteristics contd
CMPWR280
Fig 3.2. Output Voltage (Rated) vs. Temperature
3.340
Vout [V]
Fig 3.2. Output Voltage (Rated) vs. Temperature. This shows the regulator steady state performance when fully loaded (1.5A) in an ambient temperature up to the rated maximum of 70C. The output variation at maximum load is about 13mV across the normal temperature operating.
3.320
3.300
1.5A load
3.280
3.260 0 10 20 30 40 50 60 70
Ambient Temperature [ C]
Threshold [V]
Fig 3.3. Thresholds vs. Temperature. This shows the regulator select/deselect threshold variation up to the maximum rated junction temperature. The overall 125C change in junction temperature causes a 30mV variation in the select threshold voltage (regulator enable). The deselect threshold level varies about 30mV over the 125C change in junction temperature. The hysteresis remains essentially constant over the entire temperature range.
Fig 3.3. Thresholds vs. Temperature
4.8 4.7 4.6 4.5 4.4 4.3 4.2 4.1 -25 0 25 50 75 100 125 150
Vselect
Vdeselect
Junction Temperature [C]
(c)2000 California Micro Devices Corp. All rights reserved.
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Tel: (408) 263-3214
Fax: (408) 263-7846
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