MIC2025/2075 Micrel, Inc. MIC2025/2075 Single-Channel Power Distribution Switch MM8® General Description Features The MIC2025 and MIC2075 are high-side MOSFET switches optimized for general-purpose power distribution requiring circuit protection. • • • • • The MIC2025/75 are internally current limited and have thermal shutdown that protects the device and load. The MIC2075 offers “smart” thermal shutdown that reduces current consumption in fault modes. When a thermal shutdown fault occurs, the output is latched off until the faulty load is removed. Removing the load or toggling the enable input will reset the device output. • • • • • • • • Both devices employ soft-start circuitry that minimizes inrush current in applications where highly capacitive loads are employed. A fault status output flag is provided that is asserted during overcurrent and thermal shutdown conditions. The MIC2025/75 is available in the MM8® 8‑lead MSOP and 8‑lead SOP. 140mΩ maximum on-resistance 2.7V to 5.5V operating range 500mA minimum continuous output current Short-circuit protection with thermal shutdown Fault status flag with 3ms filter eliminates false assertions Undervoltage lockout Reverse current flow blocking (no “body diode”) Circuit breaker mode (MIC2075) reduces power consumption Logic-compatible input Soft-start circuit Low quiescent current Pin-compatible with MIC2525 UL File # E179633 Applications • • • • • • USB peripherals General purpose power switching ACPI power distribution Notebook PCs PDAs PC card hot swap Typical Application VCC 2.7V to 5.5V 10k Logic Controller VIN 1µF MIC2025/75 ON/OFF OVERCURRENT GND EN OUT FLG IN GND OUT NC Load NC 0.1µF UL Recognized Component MM8 is a registered trademark of Micrel, Inc. Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com June 2010 1 MIC2025/2075 MIC2025/2075 Micrel, Inc. Ordering Information Part Number Enable Temperature Range Package Active High -40°C to +85°C 8-Lead SOIC Standard Pb-Free MIC2025-1BM MIC2025-1YM MIC2025-2BM MIC2025-2YM Active Low -40°C to +85°C 8-Lead SOIC MIC2025-1BMM MIC2025-1YMM Active High -40°C to +85°C 8-Pin MSOP MIC2025-2BMM MIC2025-2YMM Active Low -40°C to +85°C 8-Pin MSOP MIC2075-1BM MIC2075-1YM Active High -40°C to +85°C 8-Lead SOIC MIC2075-2BM MIC2075-2YM Active Low -40°C to +85°C 8-Lead SOIC MIC2075-1BMM MIC2075-1YMM Active High -40°C to +85°C 8-Pin MSOP MIC2075-2BMM MIC2075-2YMM Active Low -40°C to +85°C 8-Pin MSOP Pin Configuration MIC2025/75 EN 1 8 OUT FLG 2 7 IN GND 3 6 OUT NC 4 5 NC 8-Lead SOIC (BM) 8-Lead MSOP (BMM) Pin Description Pin Number Pin Name Pin Function 1 EN Switch Enable (Input): Active-high (-1) or active-low (-2). 2 FLG Fault Flag (Output): Active-low, open-drain output. Indicates overcurrent or thermal shutdown conditions. Overcurrent condition must exceed tD in order to assert FLG. 3 GND Ground 4 NC not internally connected 5 NC not internally connected 6, 8 OUT 7 IN MIC2025/2075 Supply (Output): Pins must be connected together. Supply Voltage (Input). 2 June 2010 MIC2025/2075 Micrel, Inc. Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VIN)...........................................–0.3V to 6V Fault Flag Voltage (VFLG)............................................... +6V Fault Flag Current (IFLG)............................................. 25mA Output Voltage (VOUT).................................................... +6V Output Current (IOUT)................................ Internally Limited Enable Input (IEN)...................................... –0.3V to VIN +3V Storage Temperature (TS)......................... –65°C to +150°C ESD Rating, Note 3 Supply Voltage (VIN) . .................................. +2.7V to +5.5V Ambient Temperature (TA)........................... –40°C to +85°C Junction Temperature (TJ)......................... Internally Limited Thermal Resistance SOP (θJA)........................................................... 160°C/W MSOP(θJA)......................................................... 206°C/W Electrical Characteristics VIN = +5V; TA = 25°C, bold values indicate –40°C ≤ TA ≤ +85°C; unless noted Symbol Parameter Condition Min Typ Max Units IDD Supply Current MIC20x5-1, VEN ≤ 0.8V, (switch off), OUT = open 0.75 5 µA MIC20x5-2, VEN ≥ 2.4V, (switch off), OUT = open 0.75 5 µA MIC20x5-1, VEN ≥ 2.4V, (switch on), OUT = open 160 µA MIC20x5-2, VEN ≤ 0.8V, (switch on), OUT = open 160 µA low-to-high transition 2.1 2.4 V high-to-low transition 1.9 V 200 mV 1 µA VEN Enable Input Voltage 0.8 Enable Input Hysteresis IEN RDS(on) Enable Input Current 1 90 140 mΩ VIN = 3.3V, IOUT = 500mA 100 160 mΩ 10 µA MIC2075 (during thermal shutdown state) 50 µA OFF Current in Latched Thermal Shutdown Output Turn-On Delay tR Output Turn-On Rise Time tF Output Turnoff Fall Time ILIMIT 0.01 Switch Resistance Output Leakage Current tOFF –1 Control Input Capacitance tON VEN = 0V to 5.5V Output Turnoff Delay Short-Circuit Output Current Current-Limit Threshold VIN = 5V, IOUT = 500mA MIC2025/2075 (output off) RL = 10Ω, CL = 1µF, see “Timing Diagrams” RL = 10Ω, CL = 1µF, see “Timing Diagrams” 1 2.5 6 ms 0.5 2.3 5.9 ms 50 100 µs 50 100 µs RL = 10Ω, CL = 1µF, see “Timing Diagrams” RL = 10Ω, CL = 1µF, see “Timing Diagrams” VOUT = 0V, enabled into short-circuit. ramped load applied to output, Note 4 pF 0.5 0.7 1.25 A 0.60 0.85 1.25 A Short-Circuit Response Time VOUT = 0V to IOUT = ILIMIT (Short applied to output) 24 µs tD Overcurrent Flag Response Delay VIN = 5V, apply VOUT = 0V until FLG low 3 7 ms Undervoltage Lockout Threshold VIN rising June 2010 VIN = 3.3V, apply VOUT = 0V until FLG low VIN falling 3 1.5 1.5 3 8 ms 2.2 2.5 2.7 V 2.0 2.3 2.5 V MIC2025/2075 MIC2025/2075 Symbol Micrel, Inc. Parameter Condition Error Flag Output Resistance IL = 10mA, VIN = 5V Typ Max Units 8 25 Ω 11 40 Ω VFLAG = 5V 10 µA 140 °C 120 °C IL = 10mA, VIN = 3.3V Error Flag Off Current Overtemperature Threshold Min TJ increasing TJ decreasing Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Devices are ESD sensitive. Handling precautions recommended. Note 4. See “Functional Characteristics: Current-Limit Response” graph. Test Circuit IOUT Device Under OUT Test VOUT RL CL Timing Diagrams tR tF 90% VOUT 90% 10% 10% Output Rise and Fall Times VE N 50% tO F F tON 90% VOUT 10% Active-Low Switch Delay Times (MIC20x5-2) VE N 50% tO F F tON VOUT 90% 10% Active-High Switch Delay Times (MIC20x5-1) MIC2025/2075 4 June 2010 MIC2025/2075 Micrel, Inc. S upply On-C urrent vs . T emperature 180 160 160 100 80 3.3V 60 40 20 0 -40 -20 0 20 40 60 TEMPERATURE (°C) 100 5V 80 60 40 I OUT = 500mA 0 20 40 60 TEMPERATURE (°C) +25°C 50 +85°C V IN = 5V R L =10Ω C L =1µF 0 -40 -20 80 100 On-R es is tanc e vs . Input V oltage 5.0 0 20 40 60 TEMPERATURE (°C) 100 +25°C 50 -40°C +85°C 3.0 +25°C -40°C 2.0 1.0 R L =10Ω C L =1µF I OUT = 500mA 200 0 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 S hort-C irc uit C urrent-L imit vs . Input V oltage +25°C 700 600 500 +85°C -40°C 400 300 200 100 0 2.5 June 2010 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 5.0 5.5 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 5.0 0 2.5 5.5 C urrent-L imit T hres hold vs . T emperature 1000 2.5 V IN = 3.3V 800 V IN = 5V 600 400 200 0 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 1200 1100 1000 900 800 700 600 +85°C +25°C -40°C 500 400 300 200 100 0 2.5 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE (V) 5.0 5.5 E nable T hres hold vs . T emperature V E N R IS ING 1.5 V E N F ALLING 1.0 0.5 V IN = 5V 0 -40 -20 C urrent-L imit T hres hold vs . Input V oltage 5 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 2.0 ENABLE THRESHOLD (V) 400 V IN = 5V 1200 CURRENT LIMIT THRESHOLD (mA) CURRENT LIMIT (mA) V IN = 3.3V 600 800 0 2.5 5.5 S hort-C irc uit C urrent-L imit vs . T emperature 800 CURRENT LIMIT (mA) 5.0 CURRENT LIMIT THRESHOLD (mA) 1000 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 2.5 0 20 40 60 TEMPERATURE (°C) 80 100 E nable T hres hold vs . Input V oltage 2.0 ENABLE THRESHOLD (V) 0 2.5 80 100 T urn-O n R is e T ime vs . Input V oltage 4.0 +85°C RISE TIME (ms) RESISTANCE (mΩ) 100 2 1 150 -40°C 3 20 200 150 V IN = 3.3V 4 3.3V 0 -40 -20 80 100 S upply On-C urrent vs . Input V oltage 200 120 RISE TIME (ms) ON-RESISTANCE (mΩ) CURRENT (µA) 5V 120 T urn-O n R is e T ime vs . T emperature 5 140 140 CURRENT (µA) On-R es is tanc e vs . T emperature 5.5 V E N R IS ING 1.5 1.0 0.5 0 2.5 V E N F ALLING T A = 25°C 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 5.0 5.5 MIC2025/2075 MIC2025/2075 4 DELAY TIME (ms) 5 V IN = 3.3V 4 V IN = 5V 3 2 1 0 -40 -20 0 20 40 60 TEMPERATURE (°C) MIC2025/2075 80 100 3 F lag Delay vs . Input V oltage 3.0 2.5 +25°C 2 -40°C 1 0 2.5 UV L O T hres hold vs . T emperature V IN R IS ING +85°C UVLO THRESHOLD (V) F lag Delay vs . T emperature DELAY TIME (ms) 5 Micrel, Inc. 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 6 5.0 5.5 2.0 V IN F ALLING 1.5 1.0 0.5 0 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 June 2010 MIC2025/2075 Micrel, Inc. Functional Characteristics June 2010 7 MIC2025/2075 MIC2025/2075 MIC2025/2075 Micrel, Inc. 8 June 2010 MIC2025/2075 Micrel, Inc. Block Diagram EN OSC. THERMAL SHUTDOWN 1.2V REFERENCE UVLO CHARGE PUMP GATE CONTROL IN CURRENT LIMIT FLAG RESPONSE DELAY OUT FLG GND Functional Description Power Dissipation The device’s junction temperature depends on several factors such as the load, PCB layout, ambient temperature and package type. Equations that can be used to calculate power dissipation of each channel and junction temperature are found below. Input and Output IN is the power supply connection to the logic circuitry and the drain of the output MOSFET. OUT is the source of the output MOSFET. In a typical circuit, current flows from IN to OUT toward the load. If VOUT is greater than VIN, current will flow from OUT to IN since the switch is bidirectional when enabled. The output MOSFET and driver circuitry are also designed to allow the MOSFET source to be externally forced to a higher voltage than the drain (VOUT > VIN) when the switch is disabled. In this situation, the MIC2025/75 avoids undesirable current flow from OUT to IN. PD = RDS(on) × IOUT2 Total power dissipation of the device will be the summation of PD for both channels. To relate this to junction temperature, the following equation can be used: TJ = PD × θJA + TA where: Thermal Shutdown Thermal shutdown is employed to protect the device from damage should the die temperature exceed safe margins due mainly to short circuit faults. Each channel employs its own thermal sensor. Thermal shutdown shuts off the output MOSFET and asserts the FLG output if the die temperature reaches 140°C. The MIC2025 will automatically reset its output should the die temperature cool down to 120°C. The MIC2025 output and FLG signal will continue to cycle on and off until the device is disabled or the fault is removed. Figure 2 depicts typical timing. If the MIC2075 goes into thermal shutdown, its output will latch off and a pull-up current source is activated. This allows the output latch to automatically reset when the load (such as a USB device) is removed. The output can also be reset by toggling EN. Refer to Figure 1 for details. TJ = junction temperature TA = ambient temperature θJA = is the thermal resistance of the package Current Sensing and Limiting The current-limit threshold is preset internally. The preset level prevents damage to the device and external load but still allows a minimum current of 500mA to be delivered to the load. The current-limit circuit senses a portion of the output MOSFET switch current. The current-sense resistor shown in the block diagram is virtual and has no voltage drop. The reaction to an overcurrent condition varies with three scenarios: Switch Enabled into Short-Circuit If a switch is enabled into a heavy load or short-circuit, the switch immediately enters into a constant-current mode, reducing the output voltage. The FLG signal is asserted indicating an overcurrent condition. See the Short-Circuit Response graph under Functional Characteristics. Depending on PCB layout, package, ambient temperature, etc., it may take several hundred milliseconds from the incidence of the fault to the output MOSFET being shut off. The worst-case scenario of thermal shutdown is that of a short-circuit fault and is shown in the in the “Function Characteristics: Thermal Shutdown Response” graph. June 2010 9 MIC2025/2075 MIC2025/2075 Micrel, Inc. Fault Flag The FLG signal is an N-channel open-drain MOSFET output. FLG is asserted (active-low) when either an overcurrent or thermal shutdown condition occurs. In the case where an overcurrent condition occurs, FLG will be asserted only after the flag response delay time, tD, has elapsed. This ensures that FLG is asserted only upon valid overcurrent conditions and that erroneous error reporting is eliminated. For example, false overcurrent conditions can occur during hot-plug events when a highly capacitive load is connected and causes a high transient inrush current that exceeds the current-limit threshold. The FLG response delay time tD is typically 3ms. Short-Circuit Applied to Enabled Output When a heavy load or short-circuit is applied, a large transient current may flow until the current-limit circuitry responds. Once this occurs the device limits current to less than the short-circuit current limit specification. See the Short-Circuit Transient Response graph under Functional Characteristics. Current-Limit Response—Ramped Load The MIC2025/75 current-limit profile exhibits a small foldback effect of about 200mA. Once this current-limit threshold is exceeded the device switches into a constant current mode. It is important to note that the device will supply current until the current-limit threshold is exceeded. See the Current-Limit Response graph under Functional Characteristics. VE N Undervoltage Lockout Undervoltage lockout (UVLO) prevents the output MOSFET from turning on until VIN exceeds approximately 2.5V. Undervoltage detection functions only when the switch is enabled. Short-Circuit Faul t Load Removed (Output Reset) VOUT ILIMIT IDC IOUT Thermal Shutdown Reached VF L G tD Figure 1. MIC2075-2 Timing: Output Reset by Removing Load VE N Short-Circuit Faul t Load/Fault Removed VOUT ILIMIT IDC IOUT Thermal Shutdown Reached VF L G tD Figure 2. MIC2025-2 Timing MIC2025/2075 10 June 2010 MIC2025/2075 Micrel, Inc. Applications Information Universal Serial Bus (USB) Power Distribution The MIC2025/75 is ideally suited for USB (Universal Serial Bus) power distribution applications. The USB specification defines power distribution for USB host systems such as PCs and USB hubs. Hubs can either be self-powered or bus-powered (that is, powered from the bus). Figure 5 below shows a typical USB Host application that may be suited for mobile PC applications employing USB. The requirements for USB host systems is that the port must supply a minimum of 500mA at an output voltage of 5V ±5%. In addition, the output power delivered must be limited to below 25VA. Upon an overcurrent condition, the host must also be notified. To support hot-plug events, the hub must have a minimum of 120µF of bulk capacitance, preferably low-ESR electrolytic or tantulum. Refer to Application Note 17 for more details on designing compliant USB hub and host systems. Supply Filtering A 0.1µF to 1µF bypass capacitor positioned close to VIN and GND of the device is strongly recommended to control supply transients. Without a bypass capacitor, an output short may cause sufficient ringing on the input (from supply lead inductance) to damage internal control circuitry. Printed Circuit Board Hot-Plug The MIC2025/75 are ideal inrush current-limiters suitable for hot-plug applications. Due to the integrated charge pump, the MIC2025/75 presents a high impedance when off and slowly becomes a low impedance as it turns on. This “softstart” feature effectively isolates power supplies from highly capacitive loads by reducing inrush current during hot-plug events. Figure 3 shows how the MIC2075 may be used in a hot-plug application. For bus-powered hubs, USB requires that each downstream port be switched on or off under control by the host. Up to four downstream ports each capable of supplying 100mA at 4.4V minimum are allowed. In addition, to reduce voltage droop on the upstream VBUS, soft-start is necessary. Although the hub can consume up to 500mA from the upstream bus the hub must consume only 100mA max at start-up, until it enumerates with the host prior to requesting more power. The same requirements apply for bus-powered peripherals that have no downstream ports. Figure 6 shows a bus-powered hub. In cases of extremely large capacitive loads (>400µF), the length of the transient due to inrush current may exceed the delay provided by the integrated filter. Since this inrush current exceeds the current-limit delay specification, FLG will be asserted during this time. To prevent the logic controller from responding to FLG being asserted, an external RC filter, as shown in Figure 4, can be used to filter out transient FLG assertion. The value of the RC time constant will be selected to match the length of the transient. MIC2025-2 VC C 0.1 µF to "Hot" Receptacle 1 EN 2 OUT 8 FLG IN 7 3 GND OUT 6 4 NC NC 5 Backend Function CBULK GND Adaptor Card Figure 3. Hot Plug Application V+ Logic Controller OVERCURRENT 10k R C MIC2025 1 EN OUT 8 2 3 FLG IN 7 GND OUT 6 4 NC NC 5 Figure 4. Transient Filter June 2010 11 MIC2025/2075 MIC2025/2075 Micrel, Inc. VC C 5.0V 4.50V to 5.25V Upstream VB U S 100mA max. VB U S 10k 3.3V MIC5203-3.3 IN D+ 1µF D– 3.3V USB Controller VIN OUT 1µF GND GND Ferrite Beads MIC2025/75 ON/OFF EN OVERCURRENT GND VB U S OUT FLG IN GND OUT D+ 0.01µF 120µF GND NC NC D– USB Port 0.1µF Data Data Figure 5 USB Host Application 1.5k 3.3V USB Upstream Connector MIC5203-3.3 (LDO) VB U S IN D+ D– OUT USB Logic Controller VIN GND GND 0.1µF 0.1µF Ferrite Beads MIC2025/75 EN ON/OFF OVERCURRENT GND FLG IN GND OUT NC 1.5K VB U S OUT D+ 120µF 0.01µF D– GND NC USB Downstream Connector (Up to four ganaged ports) 0.1µF Data Data Figure 6. USB Bus-Powered Hub MIC2025/2075 12 June 2010 MIC2025/2075 Micrel, Inc. Package Information 8-Lead SOIC (M) MM8™ 8-Pin MSOP (MM) June 2010 13 MIC2025/2075 MIC2025/2075 Micrel, Inc. MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 web http://www.micrel.com This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2004 Micrel Incorporated MIC2025/2075 14 June 2010