CS2001

CS2001 1.2 A Switching Regulator, and 5.0 V, 100 mA Linear Regulator with RESET The CS2001 is a smart power supply ASIC utilized in automotive airbag systems. It contains a current−mode switching regulator with a 1.2 A on−chip switch and a 5.0 V, 100 mA linear regulator. The linear output capacitor must be 3.3 μF or greater with an ESR in the range of 100 mΩ to 1.0 Ω. If the ESR of the cap is less than 100 mΩ, a series resistor must be used. The switcher can be configured in either a boost or flyback topology. The boost topology produces energy reserve the resistor divider connected to the VFB pin. In the event of fault voltage VER which is externally adjustable (25 V maximum) through conditions that produce VFB either open or shorted, the switcher is shut down. Under normal operating conditions (VBAT > 8.0 V), the current loading on the linear regulator is directed through VBAT. A low battery or loss of battery condition switches the supply for the linear regulator from VBAT to VER and shuts down the switcher using the ASIC’s internal smart switch. This switchover feature minimizes the power dissipation in both the linear and switcher output devices and saves the cost of using a larger inductor. The NERD (No Energy Reserve Detected) pin is a dual function output. If VOUT is not in regulation, it provides a Power On Reset function whose time interval is externally adjustable with the capacitor. This interval can be seen on the RESETB pin, which allows for clean power−up and ...