MIC2505/2506 Micrel MIC2505/2506 Single 2A / Dual 1A / High-Side Switches General Description Features The MIC2505, MIC2505-1, MIC2505-2, and MIC2506 are single and dual integrated high-side power switches that consist of TTL compatible control/enable inputs, a charge pump, and protected N-channel MOSFETs. The MIC2505/6 family can be used instead of separate high-side drivers and MOSFETs in many low-voltage applications. The MIC2505/6 family controls voltages ranging from 2.7V to 7.5V. The MIC2505-series can deliver at least 2A continuous current while the MIC2506 can deliver at least 1A continuous current from each output. A slow turn-on feature prevents high inrush current when switching capacitive loads. The internal control circuitry is powered from the same 2.7V to 7.5V. Within the device’s input range, outputs can be forced higher than the input voltage when disabled. • Low MOSFET on resistance to 2.7V 30mΩ typical at 5V (MIC2505-series) 35mΩ typical at 3.3V (MIC2505-series) 75mΩ typical at 5V (each MIC2506 output) 80mΩ typical at 3.3V (each MIC2506 output) • 2.7V to 7.5V input • 110µA typical on-state supply current • 1µA typical off-state supply current • Output can be forced higher than input (off-state) • Current limit • Thermal shutdown • 2.5V undervoltage lockout (UVLO) • Open-load detection (MIC2505BN/M and MIC2506BN/M only) • Open-drain fault flag • 5ms (slow) turn-on and fast turnoff • Logic-level control/enable input Multipurpose open-drain fault flag outputs indicate overcurrent limiting, open-load detection (except MIC2505-1 and -2 versions), thermal shutdown, or undervoltage lockout for each channel. Overcurrent limiting is internally fixed and requires no external components. Open-load detection is active when the switch is off. When off, a normal load pulls the output pin low. If the load is open, an optional, external, high-value resistor pulls the output pin high, triggering the fault flag. MIC2505-1 and -2 versions are tailored to Universal Serial Bus (USB) applications and do not include open-load detection. Applications • • • • • USB Power Distribution 3.3V and 5V power management PC Card card inrush limiting switch Hot plug-in power supplies Battery-charger circuits Thermal shutdown turns off the output if the die temperature exceeds approximately 135°C. If enabled, the switch automatically restarts when the temperature falls 10°C. Undervoltage lockout (UVLO) shuts off the output if the supply drops below 2.3V typical and reenables the output when the supply exceeds 2.5V typical. Typical Applications 1 ON OFF FAULT 2 3 4 CTL OUT FLG IN GND GATE OUT IN Optional Output Delay Capacitor 100k 8 7 6 5 Optional Open Load Detect Resistor (MIC2505BN or MIC2505BM only) 0.1µF Pull-up Resistors (100k each) A ON A OFF FAULT A FAULT B B ON B OFF MIC2506BM 1 2 3 4 CTL A OUT A FLG A FLG B IN GND CTL B OUT B 100k 100k 8 7 6 Optional Open Load Detect Resistors 0.1µF 5 Load A MIC2505BM Load Pull-up Resistor (100k) 2.7V to 7.5V Load B 2.7V to 7.5V Single and Dual Switch/Circuit Breakers with Open-Load Detection and Fault Output April 1998 1 MIC2505/2506 MIC2505/2506 Micrel Ordering Information Part Number Control/Enable Open-Load Detect Temperature Range Package Single-Switch MIC2505BM Active-High Yes –40°C to +85°C 8-pin SOIC MIC2505BN Active-High Yes –40°C to +85°C 8-pin DIP MIC2505-1BM Active-High No –40°C to +85°C 8-pin SOIC MIC2505-1BN Active-High No –40°C to +85°C 8-pin DIP MIC2505-2BM Active-Low No –40°C to +85°C 8-pin SOIC MIC2505-2BN Active-Low No –40°C to +85°C 8-pin DIP MIC2506BM Active-High Yes –40°C to +85°C 8-pin SOIC MIC2506BN Active-High Yes –40°C to +85°C 8-pin DIP Dual Switch Pin Configuration MIC2505/-1/-2 MIC2506 CTL 1 8 OUT CTL A 1 8 OUT A FLG 2 7 IN FLG A 2 7 IN GND 3 6 OUT FLG B 3 6 GND GATE 4 5 IN CTL B 4 5 OUT B MIC2506 MIC2505/-1/-2 (CTL A) 1 (FLG A) 2 LOGIC, CHARGE PUMP (GATE A) 4 MIC2505/2506 6, 8 (OUT) (CTL A) 1 (FLG A) 2 LOGIC, CHARGE PUMP 5, 7 (IN) (FLG B) 3 (CTL B) 4 LOGIC, CHARGE PUMP 8 (OUT A) 7 (IN) 5 (OUT B) 3 (GND) 6 (GND) 8-Pin SOIC (M) 8-Pin DIP (N) 8-Pin SOIC (M) 8-Pin DIP (N) 2 April 1998 MIC2505/2506 Micrel Pin Description Pin Number Pin Number MIC2505 series MIC2506 Pin Name Pin Function 1 1/4 CTL (A/B) Control (Input): TTL compatible control input. High input typically > 1.8V. Low input typically < 1.6V. MIC2505, MIC2505-1 and MIC2506 are active high. MIC2505-2 is active low. 2 2/3 FLG (A/B) Fault Flag (Output): Active-low, open-drain output. If CTL is low, indicates open load. If CTL is high, indicates current limit, thermal shutdown, or UVLO. MIC2505-1 and -2 do not support open-load detect. 3 6 GND Ground: Return. 4 — GATE Output MOSFET Gate: Open for fastest rise time. Connect capacitor to ground to slow rise time. (See MIC2505 Turn-On Delay graph) 5, 7 7 IN 6, 8 8/5 OUT (A/B) Supply Input: Output MOSFET drain. Also supplies IC’s internal circuitry. Connect to supply. MIC2505 series only: Pins 5 and 7 must be externally connected together. Switch Output: Output MOSFET source. Typically connect to switched side of load. Output voltage can be pulled above input voltage in off mode. MIC2505 series only: Pins 6 and 8 must be externally connected together. Absolute Maximum Ratings Operating Ratings Supply Voltage (VIN) .................................................... 8.0V Fault Flag Voltage (VFLG) ............................................. 7.5V Fault Flag Current (IFLG) ............................................ 50mA Output Voltage (VOUT) ................................................. 7.5V Output Current (IOUT) ............................... Internally Limited Gate Voltage (VGATE) ......................................... VIN + 15V Control Input (VCTL) ....................................... –0.3V to 15V Storage Temperature (TA) ....................... –65°C to +150°C Lead Temperature (Soldering 5 sec.) ....................... 260°C Supply Voltage (VIN) ................................... +2.7V to +7.5V Ambient Operating Temperature (TA) ........ –40°C to +85°C Thermal Resistance SOIC (θJA) ......................................................... 160°C/W DIP (θJA) ............................................................ 105°C/W April 1998 3 MIC2505/2506 MIC2505/2506 Micrel Electrical Characteristics VIN = +5V; GATE = open; TA = 25°C, bold indicates –40°C ≤ TA ≤ +85°C; unless noted Parameter Condition Supply Current MIC2505-1 MIC2506 MIC2505-2 Min Typ Max Units VCTL = logic 0, OUT = open VCTL = logic 1, OUT = open 0.75 110 5 160 µA µA VCTL = logic 0, OUT = open VCTL = logic 1, OUT = open 110 0.75 160 5 µA µA 2.1 1.9 2.4 V V 0.01 0.01 1 1 µA µA VCTL = logic 0 → logic 1 transition VCTL = logic 1 → logic 0 transition Control Input Voltage Control Input Current 0.8 VCTL = logic 0 VCTL = logic 1 Control Input Capacitance Output MOSFET Resistance 1 MIC2505 series VIN = 5V, TA = 25°C VIN = 5V, –40°C < TA < +85°C VIN = 3.3V, TA = 25°C VIN = 3.3V, –40°C < TA < +85°C MIC2506 Output Turn-On Delay Output Turn-On Rise Time Output Turnoff Delay Output Turnoff Fall Time 30 35 VIN = 5V, TA = 25°C VIN = 5V, –40°C < TA < +85°C VIN = 3.3V, TA = 25°C VIN = 3.3V, –40°C < TA < +85°C 75 80 50 60 60 75 mΩ mΩ mΩ mΩ 125 150 135 165 mΩ mΩ mΩ mΩ MIC2505 series RL = 10Ω, CGATE = 0 200 850 2000 µs MIC2506 100 700 2000 µs MIC2505 series RL = 10Ω, CGATE = 0 500 3000 7500 µs MIC2506 200 2000 6000 µs MIC2505 series RL = 10Ω, CGATE = 0 0.7 20 µs MIC2506 0.8 20 µs MIC2505 series RL = 10Ω, CGATE = 0 1.5 20 µs MIC2506 0.7 20 µs 10 µA RL = 10Ω each output RL = 10Ω each output RL = 10Ω each output RL = 10Ω each output Output Leakage Current Current Limit Threshold pF MIC2505 series 2 4 A MIC2506 1 2 3 A 0.5 1 1.5 V Open Load Threshold, Note 1 VCTL = logic low, Note 2 Overtemperature Shutdown Threshold TJ increasing TJ decreasing 135 125 Error Flag Output Resistance VIN = 5V, IL = 10mA VIN = 3.3V, IL = 10mA 10 15 25 40 Ω Ω Error Flag Off Current VFLAG = 5V 0.01 1 µA UVLO Threshold VIN = increasing VIN = decreasing 2.5 2.3 2.7 2.5 V V 2.2 2.0 °C °C General Note: Devices are ESD protected, however, handling precautions recommended. General Note: All limits guaranteed by testing or statistical analysis. Note 1: MIC2505-1 and -2 versions have no open load detect feature. Note 2: Open-load threshold is the output voltage (VOUT) where FLG becomes active (low) when CTL is low. OUT is pulled high by a 100k external resistor to VIN. MIC2505/2506 4 April 1998 MIC2505/2506 Micrel Test Circuits +5V +5V 10kΩ VFLG MIC2505/-1/-2 10kΩ MIC2506BM 10kΩ A ON A OFF 10Ω CTL A OUT A CTL OUT FLG IN VFLG A FLG A IN GND OUT VFLG B FLG B GND 1µF GATE IN 10Ω B ON B OFF 10Ω 1µF CTL B OUT B Typical Characteristics Note 2 100 5 0 4 2 RL = 5Ω (IL = 1A) 0 -2 -2 0 2 4 TIME (ms) -2 6 0 2 TIME (µs) THRESHOLD VOLTAGE (V) CONTROL (V) 0 OUTPUT (V) 6 -5 4 RL = 5Ω (IL = 1A) 0 2 4 TIME (ms) -1 6 0 1 TIME (µs) 20 2 MIC2505 40 20 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 8 Error Flag Voltage vs. Error Flag Current 400 VIN RISING 2.5 VIN FALLING 2.0 On-State Supply Current vs. Supply Voltage FLG = ACTIVE 300 VDD = 3.3V 200 100 Control Threshold vs. Supply Voltage Off-State Supply Current vs. Supply Voltage 2.5 140 120 100 80 60 40 3 4 5 6 7 SUPPLY VOLTAGE (V) 8 THRESHOLD VOLTAGE (V) 160 2 VDD = 5V 0 0.1 1 10 100 ERROR FLAG CURRENT (mA) 2.0 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 60 1.5 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 2 200 180 April 1998 3 4 5 6 7 SUPPLY VOLTAGE (V) 3.0 5 -2 -2 MIC2505 40 80 UVLO Threshold Voltage vs. Temperature 10 0 60 0 4 MIC2506 Turn-On, Turnoff Characteristics 2 MIC2506 MIC2506 80 ERROR FLAG VOLTAGE (mV) OUTPUT (V) 6 -5 100 ON RESISTANCE (mΩ) 10 20 0 Output On Resistance vs. Temperature Output On Resistance vs. Supply Voltage OUTPUT RESISTANCE (mΩ) CONTROL (V) MIC2505 Turn-On, Turnoff Characteristics 1.5 1.0 0.5 0 2 3 4 5 6 7 SUPPLY VOLTAGE (V) 5 8 2.0 VCTL RISING 1.5 1.0 VCTL FALLING 2 3 4 SUPPLY VOLTAGE (V) 5 MIC2505/2506 MIC2505/2506 Micrel On-State Supply Current vs. Temperature 100 80 60 40 20 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 140 120 2.5 THRESHOLD VOLTAGE (V) 2.0 200 180 160 Control Threshold vs. Temperature Off-State Supply Current vs. Temperature 1.5 1.0 0.5 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 2.0 1.5 VCTL RISING VCTL FALLING 1 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) MIC2505 Turn-On Delay with External Gate Capacitance TURN-ON DELAY (ms) 1000 800 600 400 200 0 MIC2505/2506 0 50 100 150 200 CAPACITANCE (nF) 6 250 April 1998 MIC2505/2506 Micrel Block Diagrams CTL THERMAL SHUTDOWN OSC. 1.2V REFERENCE UVLO CHARGE PUMP IN CURRENT LIMIT GATE CONTROL Not Included in MIC2505-1, -2 OPEN LOAD DETECT OUT FLG MIC2505/2505-1/2505-2 GND GATE MIC2505-Series Block Diagram FLG A OPEN LOAD DETECT OUT A CTL A CHARGE PUMP GATE CONTROL CURRENT LIMIT OSC. THERMAL SHUTDOWN 1.2V REFERENCE UVLO CHARGE PUMP GATE CONTROL IN CURRENT LIMIT CTL B OPEN LOAD DETECT OUT B FLG B MIC2506 GND MIC2506 Block Diagram April 1998 7 MIC2505/2506 MIC2505/2506 Micrel Duplicate IN and OUT leads are not internally connected. Connect both IN pins to the supply. Connect both OUT leads to the load. Thermal Shutdown Functional Description The MIC2505-series and MIC2506 are high-side N-Channel switches. The MIC2505, MIC2505-1, and MIC2506 have active-high enable inputs. The MIC2505-2 has an active-low input. Fault conditions inhibit output transistor turn-on or turnoff when enabled. Control Input Thermal shutdown shuts off the output MOSFET and signals the fault flag if the die temperature exceeds 135°C. 10°C of hysteresis prevents the switch from turning on until the die temperature drops to 125°C. Overtemperature detection functions only when the control input is enabled (output MOSFET is on). Both MIC2506 outputs are shut off during overtemperature, and both flags will go low. Undervoltage Lockout CTL (control input) activates the oscillator, thermal shutdown, UVLO, 1.2V reference, and gate control circuits. If there are no fault conditions, the output MOSFET turns on when enabled. Reference A 1.2V bandgap reference supplies a regulated voltage to the thermal shutdown and undervoltage lockout circuits. The reference is only active when CTL is enabled. UVLO (undervoltage lockout) prevents the output MOSFET from turning on until VIN (input voltage) exceeds 2.5V typical. After the switch turns on, if VIN drops below 2.3V typical, UVLO shuts off the output MOSFET and turns the fault flag on (active low) until VIN drops below 1.5V. Undervoltage detection functions only when the control input is enabled (output MOSFET is on). Oscillator/Charge Pump The oscillator produces an 80kHz square wave output which drives the charge pump. The oscillator is enabled when CTL is active. The charge pump is a voltage quintupler (5×). The charge pump capacitors are self contained. Gate Control The gate control circuit charges the output MOSFET gate from the charge pump output or discharges the MOSFET gate to ground as determined by CTL, thermal shutdown, or UVLO (undervoltage lockout). Overcurrent Limit The overcurrent limit is preset internally. The preset level prevents damage to the output MOSFET but allows a minimum current of 2A through the output MOSFET of the MIC2505-series and 1A for each output MOSFET of the MIC2506. Output current is monitored by sensing the voltage drop across the output MOSFET drain metal resistance. Overcurrent detection functions only when the control input is enabled (output MOSFET is on) and VIN is above the UVLO threshold. An optional, external capacitor may be connected to the MIC2505 GATE to lengthen the rise time. This slows the turn on of the MOSFET output switch. (See “MIC2505 Turn-On Delay” graph.) Since this pin connects directly to the MOSFET gate, use ESD precautions when contacting components connected to this pin. Leakage resistance may increase turnon times. Input and Output Open-Load Detection Open-load detection is available only on the MIC2505 and MIC2506. The open-load detection feature is not included in the MIC2505-1 or -2 versions. Open-load detection indicates the absence of an output load by activating the fault flag. Open-load detection is optional and is enabled by connecting a high-value pull-up resistor between IN and OUT. If there is no load, the circuit detects a high OUT (output) voltage (typically ≥1V) and signals the fault flag. Under normal conditions, the low resistance of a typical load pulls OUT low. Open-load detection functions only when the control input is low (output MOSFET is off). Fault Flag FLG is an N-channel, open-drain MOSFET output. The faultflag is active (low) for one or more of the following conditions: open load (except MIC2505-1 and -2 versions), undervoltage, current limit, or thermal shutdown. The flag output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. IN (input) is the supply connection to the logic circuitry and the drain of the output MOSFET. OUT (output) is the source of the output MOSFET. In a typical circuit, current flows through the switch from IN to OUT toward the load. 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 output switch is off and VIN > UVLO minimum. In this situation, the MIC2505/6 avoids undesirable drain to body diode reverse current flow by grounding the body when the switch is off. (The conventional method for optimum turn-on threshold has the source connected to the body. This would allow a large current to flow when Vsource > Vdrain + 0.6V.) MIC2505 Series Only MIC2505/2506 8 April 1998 MIC2505/2506 Micrel U2 is off, this feature prevents current flow from the load (5V) backward through U2 to the 3.3V supply. (If a discrete MOSFET and driver were used, the MOSFET’s internal body diode would short the 5V load to the 3.3V supply.) FLG will be active (low) on any switch that is off whenever the load voltage is greater than the open load threshold (approximately 1V) except for MIC2505-1 and MIC2505-2. Applications Information Supply Filtering A 0.1µF to 1µF bypass capacitor from IN to GND, located at 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 destroy the internal control circuitry. 2.7V to 7.5V 1N4148 (optional) MIC2505BM ON OFF 1 CTL OUT U1 MIC2505BM 1 2 8 3 2 FLG IN GND OUT 7 4 3 GATE IN CTL OUT FLG IN GND GATE OUT IN U2 MIC2505BM 8 1 7 2 6 3 5 4 0.1µF 0.1µF to 1µF CTL OUT FLG IN GND OUT GATE IN 8 7 6 5 0.1µF 5 Load 4 6 +3.3V +5V Logic-High = 5V Output Logic-Low = 3.3V Output Input transients must not exceed the absolute maximum supply voltage (VIN max = 7.5V) even for a short duration. Figure 1. Supply Bypassing Figure 2. 5V/3.3V Switch Concept The bypass capacitor may be omitted only if board design precautions are followed, such as using extremely short supply leads or power and ground planes. This circuit’s function would otherwise require a dual driver, two MOSFETs, plus two diodes (or a dual driver plus four MOSFETs). Hot Plug-In Applications (Soft-Start) Control Input CTL must be driven logic high or logic low, or be pulled high or low for a clearly defined input. Floating the input may cause unpredictable operation. Add a diode clamp if negative spikes may occur. See Figure 2. Open-Load Detection The MIC2505/6 family can be used to protect the socket-side and card-side of a supply circuit from transients caused when a capacitive load is connected to an active supply. The switch presents a high impedance when off, and slowly becomes a low impedance as it turns on. This reduces the inrush current and related voltage drop that result from charging a capacitive load. Refer to “Typical Applications” (first page). Open-load detection is available only on the MIC2505 and MIC2506. For USB power distribution applications, the open-load detection feature is not included in the MIC2505-1 or -2 versions. The optional open-load detection resistor supplies a small pull-up current to the load when the output switch is off. (A 100k resistor will draw 50µA from a 5V supply.) Normally, the load dominates, pulling OUT low. If the load is absent, the optional resistor pulls OUT high, activating the fault flag if CTL is off. 3.3V 2 3 4 GND Socket CTL OUT FLG IN GND OUT GATE IN 8 7 Capacitive Load 6 5 0.1µF Card Figure 3. Hot Plug-In Concept Power Bus Switch The MIC2505/6 family features a MOSFET reverse current flow prevention circuit. This prevents current from flowing backwards (from OUT to IN) when CTL is disabled as long as VIN is above UVLO minimum. In Figure 2, when U1 is on and April 1998 MIC2505BM 1 When a load is switched off with CTL, capacitance on the output may cause the open-load function to pull the flag low until the capacitor is discharged below approximately 2.4V. Omit the pull-up resistor when open load detection is not required and for minimum off-state supply current. Power Control Circuitry A gate capacitor may be added to the MIC2505 to slow the turn on time even more, reducing the inrush current. See “MIC2505 Turn-On Delay” graph. The UVLO feature insures that each time the card is removed and VIN = 0 that the gate of the output switch is discharged to zero volts. A controlled turn-on is executed each time a board is plugged in, even with multiple insertions. 9 MIC2505/2506 MIC2505/2506 Micrel Applications Information USB Application Figure 4 depicts a low cost and robust implementation of a four-port, self-powered USB hub circuit employing ganged overcurrent protection. (+) 4.45V to 5.25V 3.5A max. (–) VBUS D+ Ferrite Bead IN D– GND 100k 33µF MIC5203-3.3 MIC5207-3.3 LDO Regulator D+ 3.3V USB Controller V+ OUT GND VBUS 1.0 µF MIC2505-2/-1 ON/OFF EN OVERCURRENT 4.7 µF IN GND OUT Downstream USB Port 1 500mA max. VBUS IN D+ 0.01µF 33µF GND D– GND 0.1µF D+ D– 33µF OUT FLG GATE 0.01µF D– GND Bold lines indicate 0.1" wide, 1-oz. copper high-current traces. Downstream USB Port 2 500mA max. VBUS D+ 0.01µF 33µF D– GND Downstream USB Port 3 500mA max. VBUS D+ 0.01µF 33µF D– GND Downstream USB Port 4 500mA max. Data Figure 4. Ganged-Switch Self-Powered Hub MIC2505/2506 10 April 1998 MIC2505/2506 Micrel Package Information 0.026 (0.65) MAX) PIN 1 0.157 (3.99) 0.150 (3.81) DIMENSIONS: INCHES (MM) 0.050 (1.27) TYP 0.064 (1.63) 0.045 (1.14) 0.197 (5.0) 0.189 (4.8) 0.020 (0.51) 0.013 (0.33) 45° 0.0098 (0.249) 0.0040 (0.102) 0°–8° 0.010 (0.25) 0.007 (0.18) 0.050 (1.27) 0.016 (0.40) SEATING PLANE 0.244 (6.20) 0.228 (5.79) 8-Pin SOIC (M) PIN 1 DIMENSIONS: INCH (MM) 0.380 (9.65) 0.370 (9.40) 0.255 (6.48) 0.245 (6.22) 0.135 (3.43) 0.125 (3.18) 0.300 (7.62) 0.013 (0.330) 0.010 (0.254) 0.018 (0.57) 0.100 (2.54) 0.130 (3.30) 0.380 (9.65) 0.320 (8.13) 0.0375 (0.952) 8-Pin DIP (N) April 1998 11 MIC2505/2506 MIC2505/2506 Micrel MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 1998 Micrel Incorporated MIC2505/2506 12 April 1998