Datasheet 1.0V to 5.5V, 1A 1ch Termination Regulators for DDR-SDRAMs BD3539FVM BD3539NUX General Description Key Specifications BD3539 is a termination regulator that complies with Termination Input Voltage Range: 1.0V to 5.5V JEDEC requirements for DDR1-SDRAM, VCC Input Voltage Range: 2.7V to 5.5V DDR2-SDRAM, and DDR3-SDRAM. This linear power VDDQ Reference Voltage Range: 1.0V to 2.75V supply uses a built-in N-channel MOSFET and Output Voltage: 1/2xV V(Typ) DDQ high-speed OP-AMPS specially designed to provide Output Current: 1.0A (Max) excellent transient response. It has a sink/source High side FET ON-Resistance: 0.35 (Typ) current capability of up to 1A and has a power supply Low side FET ON-Resistance: 0.35(Typ) bias requirement of 3.3 V (for DDR2 and DDR3) and 5.0 Standby Current: 0.5mA (Typ) V (for DDR1, DDR2, and DDR3) for driving the Operating Temperature Range: -30C to +100C N-channel MOSFET. By employing an independent reference voltage input (VDDQ) and a feedback pin Packages W(Typ) x D(Typ) x H(Max) (VTTS), this termination regulator provides excellent output voltage accuracy and load regulation as required by JEDEC standards. Additionally, BD3539 has a reference power supply output (VREF)for DDR-SDRAM or for memory controllers. Unlike the VTT output that goes to Hi-Z state, the VREF output is kept unchanged when EN input is changed to Low, making this IC suitable for DDR-SDRAM under Self Refresh state. MSOP8 2.90mm x 4.00mm x 0.90mm Features Incorporates a Push-Pull Power Supply for Termination (VTT) Incorporates a Reference Voltage Circuit (VREF) Incorporates an Enabler Incorporates an Under Voltage Lockout (UVLO) Incorporates a Thermal Shutdown Protector (TSD) Compatible with Dual Channel (DDR1, DDR2, DDR3) VSON008X2030 Usable Ceramic Capacitor at Output 2.00mm x 3.00mm x 0.60mm Applications Power Supply for DDR 1/2/3 - SDRAM Typical Application Circuit, Block Diagram VTT IN VCC VDDQ C 3 C 2 VCC VDDQ VTT IN 6 5 7 V V CC CC UVLO SOFT Ref erence VTT Block TSD 8 VTT EN TSD V CC UVLO EN C 4 UVLO TSD EN UVLO Thermal TSD V CC 3 Protection VTTS x Enable 4 V DDQ EN EN VREF 2 C 1 UVLO 1 GND Product structureSilicon monolithic integrated circuit This product has no designed protection against radioactive rays www.rohm.com TSZ02201-0J2J0A900710-1-2 2014 ROHM Co., Ltd. All rights reserved. 1/18 TSZ2211114 001 22.Jul.2015 Rev.002DatasheetDatasheet BD3539FVM BD3539NUX Pin Configurations Pin Descriptions FVM Pin Pin Name Pin Function TOP VIEW No. 1 GND Ground pin GND VTT 2 EN Enable input pin 1 8 3 VTTS Detector pin for termination voltage EN VTT IN 7 2 4 VREF Reference voltage output pin 5 VDDQ Reference voltage input pin VTTS 6 VCC 3 6 VCC VCC pin VREF 5 VDDQ 4 7 VTT IN Termination input pin 8 VTT Termination output pin NUX Pin Pin Name Pin Function No. TOP VIEW 1 VTT IN Termination input pin 2 VTT Termination output pin VTT IN VCC 1 8 3 GND Ground pin VTT 4 EN Enable input pin VDDQ 2 7 5 VTTS Detector pin for termination voltage GND 6 VREF 3 6 VREF Reference voltage output pin 7 VDDQ Reference voltage input pin EN 4 5 VTTS 8 VCC VCC pin Bottom FIN Substrate (connected to GND) Description of Blocks 1. VCC The VCC pin is for the independent power supply input that operates the internal circuit of the IC. It is the voltage at this pin that drives the ICs amplifier circuits. The VCC input ranges from 2.7V to 5.5V and maximum current consumption is 4mA. A bypass capacitor of 1 F or so should be connected to this pin when using the IC in an application circuit. 2. VDDQ This is the power supply input pin for an internal voltage divider network. The voltage at VDDQ is halved by two 100k internal voltage-divider resistors and the resulting voltage serves as reference for the VTT output. Since V =V = REF TT 1/2V , the JEDEC requirement for DDR-SDRAM can be satisfied by supplying the correct voltage to VDDQ. DDQ Noise input should be avoided at the VDDQ pin as it is also included by the voltage-divider at the output. An RC filter consisting of a resistor and a capacitor (220 and 2.2F, for instance,) may be used to reduce the noise input but make sure that it will not significantly affect the voltage-dividers output. the IC. 3. VTT IN VTT IN is the power supply input pin for the VTT output. Input voltage may range from 1.0V to 5.5V, but consideration must be given to the current limit dictated by the ON-Resistance of the IC and to the change in allowable loss due to input/output voltage difference. Generally, the following voltages are supplied: DDR3 VTT IN = 1.5V DDR2 VTT IN = 1.8V DDR1 VTT IN = 2.5V Take note that a high-impedance voltage input at VTT IN may result in oscillation or degradation in ripple rejection, so connecting a 10F capacitor with minimal change in capacitance to VTT IN terminal is recommended. However, this impedance may depend on the characteristics of the power supply input and the impedance of the PC board wiring, which must be carefully checked before use. www.rohm.com TSZ02201-0J2J0A900710-1-2 2014 ROHM Co., Ltd. All rights reserved. 2/18 TSZ22111 15 001 22.Jul.2015 Rev.002