SP2996BEN-L Datasheet, PDF (6/9 Pages) Exar Corporation – 2 Amp DDR Bus Termination Regulator

SP2996B
2 Amp DDR Bus Termination Regulator
APPLICATION INFORMATION
INTERNAL PARASITIC DIODE
Avoid forward-biasing the internal parasitic
diode, V_OUT to V_CNTL, and V_OUT to V_IN. Positive
voltage should not be applied to the output if
V_IN and V_CNTL are not present.
CONSIDERATIONS FOR DESIGNING,
RESISTANCE OF VOLTAGE DIVIDER
When the reference voltage is programmed
below 0.2V the pulldown capability of the
internal NMOS transistor is limited. It is
recommened to place a filter capacitor from
V_REF to ground in order to reduce sensitivity to
noise and improve power up characteristics
(soft start).
LAYOUT CONSIDERATIONS
The SP2996B is offered in the NSOIC-8
package, resulting in attention needing to be
paid to dissipating heat effectively when it
operates in high current. In order to prevent
maximum junction temperature from being
exceeded, suitable copper area is necessary.
The large copper area at VCNTL pins is
available, and by taking advantage of this,
much heat dissipation is attained. Use vias to
direct heat into the bottom layer as the layout
examples show below. All capacitors should be
placed as close as possible to relative pins.
TEST CIRCUITS
Testing Output Voltage Tolerance ∆V_LOAD
Testing Current in Shutdown Mode I_SHDN
© 2010 Exar Corporation
6/9
Rev. 2.0.0