A5974D STMicroelectronics

A5974D Up to 2.5 A step-down switching regulator for automotive applications Datasheet - production data Application HSOP8 - exposed pad Dedicated to automotive applications Description The A5974D is a step-down monolithic power Features switching regulator with a minimum switch current Qualified following the AEC-Q100 limit of 3.1 A, so it is able to deliver up to 2.5 A DC requirements (see PPAP for more details) current to the load depending on the application conditions. The output voltage can be set from 2.5 A DC output current 1.235 V to 35 V. The high current level is also Operating input voltage from 4 V to 36 V achieved thanks to an HSOP8 package with an 3.3 V / ( 2%) reference voltage exposed frame, that allows to reduce the R th(JA) down to approximately 40 C/W. The device uses Output voltage adjustable from 1.235 V to 35 V an internal P-channel DMOS transistor (with Low dropout operation: 100% duty cycle a typical R of 250 m) as a switching DS(on) 250 kHz internally fixed frequency element to minimize the size of the external components. An internal oscillator fixes the Voltage feed-forward switching frequency at 250 kHz. Having Zero load current operation a minimum input voltage of 4 V only it fits the Internal current limiting automotive applications requiring the device operation even in cold crank conditions. A pulse- Inhibit for zero current consumption by-pulse current limit with the internal frequency Synchronization modulation offers an effective constant current Protection against feedback disconnection short-circuit protection. Thermal shutdown Figure 1. Application schematic U1U1 VIVINN =4V TO 36V L1L1 15uH15uH TPTP22 VOVOUUTT 8 1 VCC VOUT TPTP11 6 VREF AA5974D5974D 2 SYNC R1R1 5.6K5.6K 4 5 COMP FB INH EX-PAD GND C2C2 3 9 7 C1C1 R3R3 68nF68nF 10uF10uF 10K10K D1D1 C9C9 50V50V 50V50V R2R2 C3C3 3.3K3.3K 100p100p 330uF330uF C4C4 33nF33nF TPTP33 small signal TPTP44 GNGNDD GNGNDD power plane June 2014 DocID018774 Rev 2 1/46 This is information on a product in full production. www.st.com STSTPS3L40UPS3L40UContents A5974D Contents 1 Pin settings 4 1.1 Pin connection 4 1.2 Pin description 4 2 Electrical data 5 2.1 Maximum ratings 5 2.2 Thermal data . 5 3 Electrical characteristics . 6 4 Datasheet parameters over the temperature range 8 5 Functional description . 9 5.1 Power supply and voltage reference . 9 5.2 Voltages monitor 10 5.3 Oscillator and synchronization . 10 5.4 Current protection 11 5.5 Error amplifier 12 5.6 PWM comparator and power stage . 13 5.7 Inhibit function . 14 5.8 Thermal shutdown 14 6 Additional features and protection 15 6.1 Feedback disconnection 15 6.2 Output overvoltage protection . 15 6.3 Zero load . 15 7 Closing the loop . 16 7.1 Error amplifier and compensation network 16 7.2 LC filter . 18 7.3 PWM comparator . 19 2/46 DocID018774 Rev 2