CM2026

CM2026 CHAMP | Alldatasheet

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DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Cham pion Microelectronic Corporation Page 1 GENERAL DESCRIPTION

FEATURES

The CM2026 is a dual integrated high-side power switch with independent enable and flag functions, optimized for self-powered and bus-powered Universal Serial Bus (USB) applications. Few external components are necessary to satisfy USB requirements. The CM2026 satisfies the following USB requirements: each switch channel supplies up to 500mA as required by USB downstream devices; the switch's low on-resistance meets USB voltage drop requirements; fault current is limited to typically 750mA, well below the UL 25VA safety requirements; and a flag output is available to indicate fault conditions to the local USB controller. Soft start eliminates the momentary voltage drop on the upstream port that may occur when the switch is enabled in bus-powered applications. Additional features include thermal shutdown to prevent catastrophic switch failure from high-current loads, undervoltage lockout (UVLO) to ensure that the device remains off unless there is a valid input voltage present, and 3.3V and 5V logic compatible enable inputs. The CM2026 is available in active-high version in 8-pin DIP and SOIC packages. ‹ Compliant to USB specifications ‹ UL Recognized Component ‹ 2 independent switches ‹ 3V to 5.5V input ‹ 500mA minimum continuous load current per port ‹ 140mΩ max imum on-resistance ‹ 1.25A maximum short circuit current limit ‹ Individual open-drain fault flag pins ‹ 110uA typical on-state supply current ‹ 1uA typical off-state supply current ‹ Output can be forced higher than input (off-state) ‹ Thermal shutdown ‹ 2.4V typical undervoltage lockout (UVLO) ‹ 1ms turn-on (soft-start) and fast turnoff ‹ Active-high enable version ‹ 8-pin SOIC and DIP packages

APPLICATIONS

‹ USB host and self-powered hubs ‹ USB bus-powered hubs ‹ Hot plug-in power supplies ‹ Battery-charger circuit PDIP-08/SOP-08 (Top View) EN1 FLG1 FLG2 EN2 OUT1 IN GND OUT2

DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Cham pion Microelectronic Corporation Page 2 PIN DESCRIPTION Pin No. Symbol Description 1,4 EN(1/2) 1. VIN = 3.3V, Enable (In put): Logic-compatible enable input. High i nput > 2.1V typical. Low input < 1.9V typical. Do not float. 2. V IN = 5V, Ena ble (Input): Lo gic-compatible enabl e input. High in put > 3 .5V typical. Low input < 3.3V typical. Do not float. 2,3 FLG(1/2) Fault Flag (Output): open-drain output. Indicates overcurrent, UVLO, and thermal shutdown. 6 GND Ground: Supply return. 7 IN Supply Input: Output MOSFET drain. Also supplies IC's internal circuitry. Connect to positive supply. 8,5 OUT(1/2) Switch Output: Ou tput MOSF ET source. Typically connect to s witched side of load. BLOCK DIAGRAM 4.5~5V 10K usb mcu 47K 47KCM1085 U1 CM2026 4 5 FLG1 EN1 FLG2 EN2 OUT2 GND IN OUT1 USBPORT1 10K3.3V USBPORT1 VIN 0.1U

3.3 USB CPU

ORDERING INFORMATION

Part Number Enable Temperature Range Package CM2026IS Active High -40℃ to +85℃ 8-Pin SOIC (S08) CM2026IP Active High -40℃ to +85℃ 8-Pin PDIP (P08)

DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Champion Microelectronic Corporation Page 3 ABSOLUTE MAXIMUM RATINGS (Note 1) OPERATING RATINGS (Note 2) Output Current (IOUT) …………….…… Internally Limited Storage Temperature (TS) ………………. -65 ℃ to +150 ℃ Lead Temperature (Soldering 5 sec.) ……………… 260 ℃ Ambient Operating Temperature (TA) ….. -40 ℃ to +85 ℃ Thermal Resistance

ELECTRICAL CHARACTERISTICS

VIN = +5V; TA = +25℃; unless noted CM2026 Parameter Test Conditions Min. Typ. Max. Unit Note 4, switch off, OUT = open 0.75 5 μA Supply Current Note 4, all switches on, OUT = open 110 160 μA VIN = 3.3V 2.1 Low-to-high transition VIN = 5V 3.5 V VIN = 3.3V 1.9 Enable Input Threshold High-to-low transition, Note4 VIN = 5V 3.3 V Enable input Current VEN = 0V to 5.5V -1 ±0.01 1 μA Enable Input Capacitance 1 PF VIN = 5V, IOUT = 500mA, each switch 100 140 mΩ Switch Resistance VIN = 3.3V, IOUT = 500mA, each switch 140 180 mΩ Output Turn-On Delay RL = 10Ω each output 0.5 ms Output Turn-On Rise Time RL = 10Ω each output 1 ms Output Turn-Off Delay RL = 10Ω each output 1 20 μs Output Turn-Off Fall Time RL = 10Ω each output 1 20 μs Output Leakage Current Each output (output disabled0 10 μA Continuous Load Current Each output 0.5 A Short-Circuit Current Limit Each output (enable into load), VOUT = 4.0V 0.5 0.75 1.25 A Current-Limit Threshold Ramped load applied to enabled output, VOUT≦4.0V, Note 5 1.6 2.2 A TJ increasing 135 ℃ Overtemperature Shutdown Threshold TJ decreasing 125 ℃ Error Flag Output Resistance VIN = 5V, IL = 10mA 10 25 Ω VIN = 3.3V, IL = 10mA 15 40 Ω Error Flag Off Current VFLG = 5V 0.01 1 μA VIN = increasing 2.5 V UVLO Threshold VIN = decreasing 2.3 V 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 5. See "Functional Characteristics: Current-Limit Response" photo.

DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Champion Microelectronic Corporation Page 4 FUNCTIONAL DESCRIPTION The CM2026 is dual high-side switch with active-high enable inputs, respectively. Fault conditions turn off or inhibit turn-on of one or more of the output transistors, depending upon the type of fault, and activate the open-drain error flag transistors making them sink current to ground. Input and Output IN (input) is the power supply connection to the logic circuitry and the drain of the output MOSFET. OUTx (output) is the source of its respective MOSFET. In a typical circuit, current flows through the switch from IN to OUT toward the load. If V OUT is greater than VIN when a switch is enabled, current will flow from OUT to IN since the MOSFET is bi-directional when on. The output MOSFET and driver circuitry are also designed to allow the MOSFET source to be externally forced to a higher voltage than drain (VOUT > VIN) when the output is off. In this situation, the CM2026 avoids undesirable current flow from OUT to IN. If VIN < 2.5V, UVLO disables both switches. Thermal Shutdown Thermal shutdown shuts off the affected output MOSFETs and signals all fault flags if the die temperature exceeds 135 ℃. 10℃ of hysteresis prevents t he switch from turning on until the die temperature drops to 125℃. Overtemperature detection functions only when at least one switch is enabled. Current Limit Induced Thermal Shutdown Internal circuitry increases the output MOSFET on-resistance until the series combination of the MOSFET on-resistance and the load impedance limit current to typically 850mA. The increase in power dissipation, in most cases, will cause the CM2026 to go into thermal shutdown, disabling affected channels. When this is undesirable, thermal shutdown can be avoided by externally responding to the fault and disabling the current limited channel before the shutdown temperature is reached. The delay between the flag indication of a current limit fault and thermal shutdown will vary with ambient temperature, board layout, and load impedance, but is typically several hundred milliseconds, The USB controller must therefore recognize a fault and disable the appropriate channel with this time. If the fault is not removed or the switch is not disabled with the time, then the device will enter into a thermal oscillation of about 2Hz. This does not cause any damage to the device. Refer to "Functional Characteristics: Thermal Shutdown Response." Undervoltage Lockout UVLO (undervoltage lockout) prevents the output MOSFET from turning on until VIN exceeds approximately 2.5V. In the undervoltage state, the FLAG will be low. After the switch turns on, if the voltage drops below approximately 2.3V, UVLO shuts off the output MOSFET and signals fault flag. Undervoltage detection functions only when at least one switch is enabled. Current Sensing and Limiting The current-limit threshold is preset internally. The preset level prevents damage to the output MOSFET and external load but allows a minimum current of 0.5A through the output MOSFET of each channel. The current-limit circuit senses a portion of the output FET 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 powered on or enabled into a heavy load or short circuit, the switch immediately goes into a constant current mode, reducing the output voltage. The fault flag goes low until the load is reduced. Short Circuit Applied to Output When a heavy load is applied, a large transient current may flow until the current limit circuitry will respond. Once this occurs, the device limits current to less than the short-circuit current limit specification. Current-Limit Response The CM2026 current-limit profile exhibits a small foldback effect of approximately 500mA. Once this current-limit threshold is exceeded the device enters constant current mode. Fault Flag FLG is an N-channel, open-drain MOSFET output. The fault flag is active (low) for one or more of the following conditions: undervoltage (while 2V<V IN<2.7V), current limit, or thermal shutdown. The flag output MOSFT is capable of sinking a 10mA load to typically 100mV above ground. Multiple FLG pins may be "wire NORed" to a common pull-up resistor.

DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Champion Microelectronic Corporation Page 5 APPLICATIONS INFORMATION Supply Filtering A 0.1μF to 0.1μF 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 damage internal control circuitry. Input or output transients must not exceed the absolute maximum supply voltage (VIN max = 6V) even for a short duration. Enable Input EN must be driven logic high or logic 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. Soft Start The CM2026 presents a high impedance when off, and slowly becomes a low impedance as it turns on. This reduces inrush current and related voltage drop that results from charging a capacitive load, satisfying the USB voltage droop requirements for bus-powered applications as shown in Figure The soft start circuit shown in Figure 3 can be utilized to meet USB transient regulation specifications with large load capacitances (CBULK > 10uF). The CM2026 will provide inrush current limiting for these applications. Transient Overcurrent Filter When the CM2026 is enabled, large values of capacitance at the output of the device will cause inrush current to exceed the short circuit current-limit threshold of the device and assert the flag. The duration of this time will depend on the size of the output capacitance. Refer to the "Functional Characteristics" turn-on and turnoff behaviors for details. During the capacitance charging time, the device enters into constant-current mode. As the capacitance is charged, the current decreases below the short circuit current-limit threshold old, and the flag will then be deserted. In USB applications, it is required that output bulk capacitance is utilized to support hot-plug events. When the CM2026 is enabled, the flag may go active for about 1ms due to inrush current exceeding the current-limit setpoint. Additionally, during hot-plug events, inrush currents may also cause the flag to go active for 30uS. Since these conditions are not valid overcurrent faults, the USB controller must ignore the flag during these events. To prevent this erroneous overcurrent reporting, a 1ms RC filter as shown in Figure 4 may be programmed into the USB logic controller, eliminating the need for the RC filter.

DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Cham pion Microelectronic Corporation Page 6 PACKAGE DIMENSION 8-PIN PDIP (P08) θ PIN 1 ID θ 8-PIN SOP (S08) PIN 1 ID θ θ

DUAL USB P OWER C ONTROL S WITCH 2002/05/29 Rev. 2 Champion Microelectronic Corporation Page 7 IMPORTANT NOTICE Champion Microelectronic Corporation (CMC) reserves the right to make changes to its products or to discontinue any integrated circuit product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information being relied on is current. A few applications using integrated circuit products may involv e potential risks of death, personal injury, or severe property or environmental damage. CMC integrated circ uit products are not designed, intended, authorized, or warranted to be suitable for use in life-support applications, devices or systems or other critical applications. Use of CMC products in such applications is understood to be fully at the risk of the cust omer. In order to minimize risks associated with the customer’s applications, th e customer should provide adequate design and operating safeguards. HsinChu Headquarter Sales & Marketing 5F, No. 11, Park Avenue II, Science-Based Industrial Park, HsinChu City, Taiwan 11F, No. 306-3, SEC. 1, Ta Tung Road, Hsichih, Taipei Hsien 221, Taiwan T E L : +886-3-567 9979 T E L :+886-2-8692 1591 FAX: +886-3-567 9909 FAX: +886-2-8692 1596