MIC2545A/2549A Micrel MIC2545A/2549A Programmable Current Limit High-Side Switch Preliminary Information General Description Features The MIC2545A and MIC2549A are integrated high-side power switches optimized for low loss dc power switching and other power management applications, including Advanced Configuration and Power Interface (ACPI). The MIC2545A/ 49A is a cost-effective, highly integrated solution that requires few external components to satisfy USB and ACPI requirements. • • • • • • • • • • • Load current management features include a precision resistor-programmable output current-limit and a soft-start circuit, which minimizes inrush current when the switch is enabled. Thermal shutdown, along with adjustable current-limit, protects the switch and the attached device. The MIC2545A/49A’s open-drain flag output is used to indicate current-limiting or thermal shutdown to a local controller. The MIC2549A has an additional internal latch which turns the output off upon thermal shutdown, providing robust fault control. The enable signal is compatible with both 3V and 5V logic, and is also used as the thermal shutdown latch reset for the MIC2549A. The MIC2545A and MIC2549A are available in active-high and active-low enable versions in 8-pin DIP, SOIC, and TSSOP packages. 2.7V to 5.5V input Adjustable current-limit up to 3A Reverse current flow blocking 90µA typical on-state supply current 1µA typical off-state supply current 50mΩ maximum on-resistance Open-drain fault flag Thermal shutdown Thermal shutdown output latch (MIC2549A) 2ms (slow) soft-start turn-on, fast turnoff Available with active-high or active-low enable Applications • • • • • • USB power distribution PCI Bus Power Switching Notebook PC ACPI power distribution PC card hot swap applications Inrush current-limiting Typical Application +5V MIC2545A 10k On/Off EN OUT FLG IN GND OUT ILIM IN RSET 0.1µF Peripheral 33µF Typical Advanced Configuration and Power Interface (ACPI) Application Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com June 2000 1 MIC2545A/2549A MIC2545A/2549A Micrel Ordering Information Part Number Temperature Range Package MIC2545A-1BM Active High Enable Latch* –40°C to +85°C 8-lead SOP MIC2545A-1BN Active High –40°C to +85°C 8-pin DIP MIC2545A-1BTS Active High –40°C to +85°C 14-lead TSSOP MIC2545A-2BM Active Low –40°C to +85°C 8-lead SOP MIC2545A-2BN Active Low –40°C to +85°C 8-pin DIP MIC2545A-2BTS Active Low –40°C to +85°C 14-lead TSSOP MIC2549A-1BM Active High • –40°C to +85°C 8-lead SOP MIC2549A-1BN Active High • –40°C to +85°C 8-pin DIP MIC2549A-1BTS Active High • –40°C to +85°C 14-lead TSSOP MIC2549A-2BM Active Low • –40°C to +85°C 8-lead SOP MIC2549A-2BN Active Low • –40°C to +85°C 8-pin DIP MIC2549A-2BTS Active Low • –40°C to +85°C 14-lead TSSOP Pin Configuration MIC2545A/2549A MIC2545A/2549A EN 1 8 OUT FLG 2 7 IN GND 3 6 OUT ILIM 4 5 IN EN 1 14 OUT NC 2 13 NC FLG 3 12 IN NC 4 11 NC 10 OUT GND 5 8-Lead SOP (M) 8-Pin DIP (N) NC 6 9 NC ILIM 7 8 IN MIC2545A/2549A LOGIC, CHARGE PUMP (EN) 1 (FLG) 2 6,8 (OUT) 14-Lead TSSOP (TS) 5,7 (IN) (ILIM) 4 3 (GND) Pin Description Pin Number SOP, DIP Pin Number TSSOP Pin Name 1 1 EN Enable (Input): Logic-compatible enable input (-1 version is active high, -2 version is active low). High input >1.8V typical; low input <1.4V typical. Do not float. MIC2549A only: Also resets thermal shutdown latch. 2 3 FLG Fault Flag (Output): Active-low, open-drain output. Indicates overcurrent or thermal shutdown. MIC2549A only: latched low on thermal shutdown. 3 5 GND Ground: Supply return. 4 7 ILIM Current Limit: Sets current limit threshold using an external resistor (RSET) connected to ground. 76.8Ω < RSET < 459Ω. 5, 7 8, 12 IN Supply Input: Output MOSFET drain. Also powers internal circuitry. Both IN pins must be externally connected together. 6, 8 10, 14 OUT Switch Output: Output MOSFET source. Both OUT pins must be externally connected together. 2,4,6,9,11,13 NC MIC2545A/2549A Pin Function not internally connected 2 June 2000 MIC2545A/2549A Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VIN) .................................................. +6.0V Output Voltage (VOUT) ............................................... +6.0V Output Current (IOUT) ............................... Internally Limited Enable Input (VEN) ......................................... –0.3V to +6V Fault Flag Voltage (VFLG) ........................................... +6.0V Fault Flag Current (IFLG) ............................................ 50mA Storage Temperature (TS) ....................... –65°C to +150°C Junction Temperature (TJ) ....................... Internally Limited Lead Temperature (soldering 5 sec.) ........................ 260°C ESD Rating, Note 3 .................................................. 2000V Supply Voltage (VIN) ................................... +2.7V to +5.5V Ambient Temperature Range (TA) ............. –40°C to +85°C Package Thermal Resistance PDIP (θJA) ......................................................... 130°C/W SOIC (θJA) ......................................................... 160°C/W TSSOP (θJA), Note 6 ........................................ 100°C/W Current Limit Set Range, Note 5 ........................ 0.5A to 3A Electrical Characteristics VIN = +5V; TA = 25°C, bold indicates –40°C to +85°C; unless noted Symbol VEN Parameter Condition Supply Current Enable Input Voltage Enable Input Current RDS(on) Min Typ Max Units Switch off, OUT = open, Note 4 0.75 5 µA Switch on, OUT = open, Note 4 90 125 150 µA µA Enable high transition, Note 4 2.4 1.6 V Enable low transition, Note 1 1.5 0.8 V VEN = VOH(min) = 2.4V 0.01 1 µA VEN = VOL(max) = 0.8V 0.01 1 µA Enable Input Capacitance Note 7 1 pF Switch Resistance IOUT = 500mA 35 50 mΩ Current Limit Factor ILIMIT = 0.5A to 3A, VOUT = 1V to 4V, Note 5 160 230 300 V ILIMIT = 1A to 2.5A, VOUT = 1V to 4V, Note 5 184 230 276 V 1 10 µA Output Leakage Current Switch off, VOUT = 0V tON Output Turn-On Delay RL = 10Ω, CL = 1µF, Figures 1a, 1b 1 2 5 ms tR Output Turn-On Rise Time RL = 10Ω, CL = 1µF, Figure 1a, 1b 0.75 1.8 4.9 ms tOFF Output Turnoff Delay RL = 10Ω, CL = 1µF, Figure 1a, 1b 25 µs tF Output Turnoff Fall Time RL = 10Ω, CL = 1µF, Figure 1a, 1b 23 µs Overtemperature Threshold Shutdown TJ increasing 135 °C TJ decreasing 120 °C Error Flag Off Current VFLG = 5V 0.01 EN Pulse Reset Width MIC2549A thermal shutdown latch, Note 7 1 µs VIN to EN Set-Up MIC2549A, Note 7, Figure 1c 0 µs Current-Limit Response Time VOUT = 0V to IOUT = 2A, ISET = 1A, Note 7 40 Error Flag Output Resistance IFLG = 10mA 4 tSU VOL 1 µA µs 15 Ω 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. Human body model, 1.5k in series with 100pF. Note 4. Off is ≤ 0.8V and on is ≥ 2.4V for the MIC2545A-1 and MIC2549A-1. Off is ≥ 2.4V and on is ≤ 0.8V for the MIC2545A-2 and MIC2549A-2. The enable input has about 100mV of hysteresis. Note 5. 230 Current limit is determined by: ILIMIT = R , where RSET is in ohms, and 230 is typical current limit factor in volts. SET Note 6. Assumes 4 layer PCB is used. Note 7. Guaranteed by design but not production tested. June 2000 3 MIC2545A/2549A MIC2545A/2549A Micrel Test Circuit VOUT Device Under OUT Test IOUT RL CL tr tf 90% 90% VOUT 10% 10% Functional Characteristics Test Circuit Timing Diagrams VEN 50% tOFF tON 90% VOUT 10% Figure 1a. MIC2545A/49A-2 VEN 50% tOFF tON 90% VOUT 10% Figure 1b. MIC2545A/49A-1 VIN tSU VEN Figure 1c. Input-to-Enable Setup Timing MIC2545A/2549A 4 June 2000 MIC2545A/2549A Micrel Output Reset Short-Circuit Fault EN VOUT ILIMIT Fault Removed IDC IOUT Thermal Shutdown Reached FLG Figure 2a. MIC2549A-2 Timing: Output Is Reset By Toggling EN EN Short-Circuit Fault Fault Removed VOUT ILIMIT IDC IOUT Thermal Shutdown Reached FLG Figure 2b. MIC2545A-2 Timing June 2000 5 MIC2545A/2549A MIC2545A/2549A Micrel Typical Characteristics Output On-Resistance vs. Supply Voltage Output On-Resistance vs. Temperature 37 36 TA = 27°C 35 34 33 32 31 30 2.5 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) 45 3.3V 40 2.7V 35 30 25 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 5.5 5.0V 3.3V 60 2.7V 40 20 0.4 0.3 5.0V 0.2 3.3V 0.1 2.7V 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) Control Threshold Voltage vs. Supply Voltage Control Threshold Voltage vs. Temperature TA = 27°C HIGH 1.5 1.4 1.3 1.2 LOW 1.1 1.0 2.5 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) 5.5 1.0 3.3V 0.8 0.6 5.0V 0.4 0.2 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) MIC2545A/2549A 0.01 0 2.5 3.5 HIGH 1.6 1.5 LOW 1.4 1.3 1.2 5.5 2.7V 3.0 2.5 3.3V 2.0 5.0V 1.5 1.0 RL = 44Ω 0.5 Output Current vs. Output Voltage 3500 VIN = 5V 3000 2500 2000 1500 ITH 1000 ILIMIT 500 0 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) OUTPUT CURRENT (mA) 1.2 0.03 0.02 4.0 1.7 TA = 27°C Current Limit vs. Rset CURRENT LIMIT (mA) 2.7V 5.5 0.05 0.04 1.8 3500 RL = 44Ω CL = 0µF 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) 0.07 0.06 1.9 Output Fall Time vs. Temperature 1.4 20 Rise Time vs. Temperature 1.1 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 1.8 1.6 40 0.09 0.08 OUTPUT RISE TIME (ms) CONTROL THRESHOLD (V) 2.0 1.7 1.6 60 0.10 RL = 44Ω 0 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) 1.9 1.8 80 Off-State Supply Current vs. Supply Voltage SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 120 80 TA = 27°C 100 0 2.5 0.5 100 120 Off-State Supply Current vs. Temperature 140 THRESHOLD VOLATAGE (V) 5.0V SUPPLY CURRENT (µA) 39 38 140 On-State Supply Current vs. Temperature OUTPUT FALL TIME (µs) On-State Supply Current vs. Supply Voltage 50 OUTPUT RESISTANCE (mΩ) OUTPUT RESISTANCE (mΩ) 40 ISHORT 0 150 300 RSET (Ω) 6 450 600 RSET = 92 3000 2500 VIN = 5V 2000 1500 RSET = 230 1000 500 0 RSET = 460 0 1.0 2.0 3.0 4.0 5.0 OUTPUT VOLTAGE (V) 6.0 June 2000 MIC2545A/2549A Micrel 1500 1400 1300 1200 1200 VIN = 5V RSET = 230Ω ITH 1100 1000 900 800 700 600 Current Limit vs. Supply Voltage CURRENT LIMIT (mA) OUTPUT CURRENT (mA) Current Limit vs. Temperature ISET ISHORT 500 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) June 2000 1000 TA = 27°C RL = 230Ω ISET 900 800 ISHORT 700 600 2.5 7 ITH 1100 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) 5.5 MIC2545A/2549A MIC2545A/2549A Micrel Functional Characteristics VFLG VEN (10V/div.) (10V/div.) VOUT (2V/div.) 500mA VIN = 5V CL = 100µF RL = 10Ω IOUT (200mA/div.) IOUT (200mA/div.) Turnoff Response VOUT VFLG VEN (2V/div.) (10V/div.) (10V/div.) Turn-On Response VIN = 5V CL = 100µF RL = 10Ω 500mA MIC2545A-1 MIC2545A-1 TIME (1ms/div.) TIME (500µs/div.) Load Removed Current-Limit Threshold 1.12A Short-Circuit Current 820mA (ISHORT) IOUT (500mA/div.) Current-Limit Threshold 1.12A (ITH) ISET = 1A IOUT (500mA/div.) Short Circuit VOUT (5V/div.) VOUT (5V/div.) Thermal Shutdown C = 5V RL = 1Ω Thermal Shutdown VIN = 5V MIC2545A-1 MIC2545A-1 TIME (100ms/div.) Enable Into Short Circuit Inrush Current Response VFLG VEN (10V/div.) (10V/div.) VFLG VEN (10V/div.) (10V/div.) TIME (100ms/div.) Thermal Shutdown MIC2545A-1 TIME (100ms/div.) MIC2545A/2549A VIN = 5V RL = 10Ω CL = 490µF CL = 130µF Short-Circuit Current 820mA VIN = 5V RSET = 240Ω IOUT (500mA/div.) VOUT (5V/div.) IOUT (500mA/div.) Short-Circuit Response VFLG VEN (10V/div.) (10V/div.) VFLG VEN (10V/div.) (10V/div.) Current-Limit Response CL = 10µF MIC2545A-1 TIME (500µs/div.) 8 June 2000 MIC2545A/2549A Micrel VEN VFLG (5V/div.) (10V/div.) Thermal Shutdown (Output Reset by Toggling Enable—MIC2549-1) Ramped Load to a Short VOUT (5V/div.) Output Reset Output Latched IOUT (500mA/div.) Thermal Shutdown VIN = 5V CL = 47µF TIME (100ms/div.) June 2000 9 MIC2545A/2549A MIC2545A/2549A Micrel Block Diagram EN IN OSC. THERMAL SHUTDOWN 1.2V REFERENCE CHARGE PUMP CURRENT LIMIT IN ILIM RSET GATE CONTROL RESET THERMAL SHUTDOWN LATCH (MIC2549A) OUT OUT FLG GND MIC2545A/2549A 10 June 2000 MIC2545A/2549A Micrel The current-limit response of the MIC2545A/49A is based on the type of load that is applied to the output and is defined in three parts: 1. The first mode of operation is where the device enters a constant-current mode preventing further increases in output current. The value of this current, ILIMIT, is defined by the value of RSET as explained further in this section. 2. When a short circuit is applied to the output of an enabled device the output current immediately folds back to a value less than ILIMIT called ISHORT. This further protects the load and reduces device power dissipation. Refer to the “Typical Characteristics: Output Current vs. Output Voltage” graph for details. 3. When a load is increased, the output current will proportionally increase up to the current-limit threshold, ITH, as shown in the “Functional Characteristics: Current-Limit Response” graph. The device in this case will supply current slightly higher than the current-limit set point defined by RSET. As the load is increased further the current folds back to ILIMIT. The nominal current-limit value, ILIMIT, is set with an external resistor between ILIM (pin 4) and GND (pin 3). For a desired current-limit, the value of the external set resistor is given by: Functional Description The MIC2545A and MIC2549A are high-side N-channel switches available with active-high or active-low enable inputs. Fault conditions turn off or inhibit turn-on of the output transistor and activate the open-drain error flag transistor making it sink current to ground. 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 MIC2545A/49A avoids undesirable current flow from OUT to IN. Both IN pins must be connected together, and both OUT pins must be connected together. Thermal Shutdown 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 switch is enabled. The MIC2549A features an internal latch which causes the part to remain off after thermal shutdown until a reset pulse is provided via the enable pin (pin 1). While in current-limit, the thermal shutdown latch prevents on/off cycling of the output. Refer to Figure 2 for timing diagram. The flag remains low until reset. 230 RSET = ILIMIT where: 76.8Ω < RSET < 459Ω Enable Input EN 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. EN should not be allowed to go negative with respect to GND. Current-Limit Operation For example, to set a 1A nominal current-limit, RSET is calculated as: 230 = 230Ω 1A Refer to the “Typical Characteristics: Current-Limit vs RSET” graph for more details. Current through RSET increases with output current. The voltage across RSET could be monitored with a high impedance comparator to provide an indication of output current. RSET should be between 76.8Ω and 459Ω (1% resister value). Fault Flag The current limit is user adjustable with an external set resistor. Current limiting in the range of 500mA to 3A is available with a set point accuracy of better than ±30% (±20% for ISET 1 to 2.5A). The current-limit circuit prevents damage to the output MOSFET and external load. FLG is an N-channel, open-drain MOSFET output. The faultflag is active (low) for current-limit or thermal shutdown conditions. The flag output MOSFET is capable of sinking a 10mA load to typically 100mV above ground. For applications with VIN ≤ 3.6V, it is recommended that flag current be limited to 5mA or less. June 2000 11 MIC2545A/2549A MIC2545A/2549A Micrel TJ = junction temperature TA = ambient temperature Applications Information Supply Filtering θJA = is the thermal resistance of the package A 0.1µF to 1µF bypass capacitor from IN to GND, located near the MIC2545A and MIC2549A, 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. Input transients must not exceed the absolute maximum supply voltage (VIN max = 6V) even for a short duration. Transient Overcurrent Filter The inrush current from the connection of a heavy capacitive load may cause the fault flag to fall for 10µs to 200µs while the switch is in a constant-current mode, charging the capacitance. Adding an optional series resistor-capacitor (RSET2) in parallel with RSET, as shown in Figure 4, allows the transient current-limit to be set to a different value than steady state. A typical USB hot-plug inrush is 2A to 3A for 10µs to 20µs. If RSET is 435Ω (530mA), an RSET2 of 88Ω (2.5A) and CSET of 1µF (RC ≈ 90µs) allows transient surge of 3A to pass for 90µs without tripping the overcurrent flag (FLG). USB Power Distribution 4.0V to 5.5V MIC2549A-1BM 1 EN 2 3 4 OUT FLG IN GND OUT ILIM IN 8 7 0.1µF to 1µF 6 5 RSET The MIC2545A is ideal for meeting USB power distribution requirements. Figure 7 depicts a USB Host application. RSET should be set to a value providing a current-limit >500mA. The accurate current-limit of the MIC2545A will reduce power supply current requirements. Also, fast reaction to short circuit faults prevent voltage droop in mobile PC applications. Printed Circuit Board Hot-Plug The MIC2545A/49A is an ideal inrush current-limiter suitable for hot-plug applications. Due to the integrated charge pump, the MIC2545A/49A 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 5 shows how the MIC2545A may be used in a hot-plug application. Figure 3. Supply Bypassing 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 and junction temperature are found below. Calculation of power dissipation can be accomplished by the following equation: PD = RDS(on) × (IOUT)2 To relate this to junction temperature, the following equation can be used: TJ = PD × θJA + TA where: Ferrite Bead 5V (+) 10k 4.7µF (–) VBUS D+ IN D– 3.3V USB Controller V+ OUT GND VBUS D+ MIC5203-3.3 LDO Regulator 1.0 µF ON/OFF EN OVERCURRENT GND 1.5k 2% MIC2545A-2 0.1µF FLG IN GND OUT ILIM IN D– GND 0.1µF D+ D– 0.01µF 120µF OUT Downstream USB Port 1 4.75V min. 500mA max. GND RSET RSET(2) CSET Bold lines indicate 0.1" wide, 1-oz. copper high-current traces. (optional) Figure 4. USB Host Application MIC2545A/2549A 12 June 2000 MIC2545A/2549A Micrel MIC2545A-2 1 VCC 2 to "Hot" Receptacle 0.1 µF 3 4 EN OUT FLG IN GND OUT ILIM IN 8 7 Backend Function 6 5 CBULK 0.1µF GND Adaptor Card Figure 5. Hot-Plug Application June 2000 13 MIC2545A/2549A MIC2545A/2549A Micrel Package Information 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) 0.130 (3.30) 0.100 (2.54) 0.380 (9.65) 0.320 (8.13) 0.0375 (0.952) 8-Pin DIP (N) 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) 0.0098 (0.249) 0.0040 (0.102) 0°–8° SEATING PLANE 45° 0.010 (0.25) 0.007 (0.18) 0.050 (1.27) 0.016 (0.40) 0.244 (6.20) 0.228 (5.79) 8-Pin SOIC (M) MIC2545A/2549A 14 June 2000 MIC2545A/2549A Micrel 4.50 (0.177) 6.4 BSC (0.252) 4.30 (0.169) DIMENSIONS: MM (INCH) 0.30 (0.012) 0.19 (0.007) 5.10 (0.200) 4.90 (0.193) 0.20 (0.008) 0.09 (0.003) 1.10 MAX (0.043) 0.65 BSC (0.026) 0.15 (0.006) 0.05 (0.002) 8° 0° 1.00 (0.039) REF 0.70 (0.028) 0.50 (0.020) 14-Pin TSSOP (TS) June 2000 15 MIC2545A/2549A MIC2545A/2549A 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. © 2000 Micrel Incorporated MIC2545A/2549A 16 June 2000