link to page 4 link to page 4 link to page 4 link to page 4 link to page 4 link to page 4 link to page 4 link to page 4 link to page 2 CS5171, CS5172, CS5173, CS5174ELECTRICAL CHARACTERISTICS (2.7 V< VCC < 30 V; Industrial Grade: −40°C < TJ < 125°C; Commercial Grade: 0°C < TJ < 125°C; For all CS5171/2/3/4 specifications unless otherwise stated.) CharacteristicTest ConditionsMinTypMaxUnitPower Switch Switch Saturation Voltage ISWITCH = 1.5 A, (Note 3) − 0.8 1.4 V ISWITCH = 1.0 A, 0°C ≤ TJ ≤ 85°C − 0.55 − V ISWITCH = 1.0 A, −40°C ≤ TJ ≤ 0°C − 0.75 − V ISWITCH = 10 mA − 0.09 0.45 V Switch Current Limit 50% duty cycle, (Note 3) 1.6 1.9 2.4 A 80% duty cycle, (Note 3) 1.5 1.7 2.2 A Minimum Pulse Width FB = 0 V or NFB = 0 V, ISW = 4.0 A, (Note 3) 200 250 300 ns DICC/ DIVSW 2.7 V ≤ VCC ≤ 12 V, 10 mA ≤ ISW ≤ 1.0 A − 10 30 mA/A 12 V < VCC ≤ 30 V, 10 mA ≤ ISW ≤ 1.0 A − − 100 mA/A 2.7 V ≤ VCC ≤ 12 V, 10 mA ≤ ISW ≤ 1.5 A, (Note 3) − 17 30 mA/A 12 V < VCC ≤ 30 V, 10 mA ≤ ISW ≤ 1.5 A, (Note 3) − − 100 mA/A Switch Leakage VSW = 40 V, VCC = 0V − 2.0 100 mA General Operating Current ISW = 0 − 5.5 8.0 mA Shutdown Mode Current VC < 0.8 V, SS = 0 V, 2.7 V ≤ VCC ≤ 12 V − 12 60 mA VC < 0.8 V, SS = 0 V, 12 V ≤ VCC ≤ 30 V − − 100 Minimum Operation Input Voltage VSW switching, maximum ISW = 10 mA − 2.45 2.70 V Thermal Shutdown (Note 3) 150 180 210 °C Thermal Hysteresis (Note 3) − 25 − °C 3. Guaranteed by design, not 100% tested in production. Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. PACKAGE PIN DESCRIPTIONPackagePinPin #SymbolFunction 1 VC Loop compensation pin. The VC pin is the output of the error amplifier and is used for loop compensation, current limit and soft start. Loop compensation can be implemented by a simple RC network as shown in the application diagram on page 2 as R1 and C1. 2 FB Positive regulator feedback pin. This pin senses a positive output voltage and is referenced to 1.276 V. When (CS5171/3 the voltage at this pin falls below 0.4 V, chip switching frequency reduces to 20% of the nominal frequency. only) 2 Test These pins are connected to internal test logic and should either be left floating or tied to ground. Connection (CS5172/4) to a voltage between 2 V and 6 V shuts down the internal oscillator and leaves the power switch running. 3 CS5171/3) 3 NFB Negative feedback pin. This pin senses a negative output voltage and is referenced to −2.5 V. When the (CS5172/4) voltage at this pin goes above −0.65 V, chip switching frequency reduces to 20% of the nominal frequency. 4 SS Synchronization and shutdown pin. This pin may be used to synchronize the part to nearly twice the base frequency. A TTL low will shut the part down and put it into low current mode. If synchronization is not used, this pin should be either tied high or left floating for normal operation. 5 VCC Input power supply pin. This pin supplies power to the part and should have a bypass capacitor connected to AGND. www.onsemi.com4