MP2364 Datasheet, PDF (4/12 Pages) Monolithic Power Systems – Dual 1.5A, 23V, 1.4MHz Step-Down Converter

TM
MP2364 — DUAL 1.5A, 23V, 1.4MHz STEP-DOWN CONVERTER
PIN FUNCTIONS (TSSOP20F)
Pin # Name Description
1
SSA
Soft-Start Control for Channel A. 9kΩ output resistance from the pin. Set RC time constant
with external capacitor for soft start ramp time. Ramp Time = 2.2 x 9kΩ x C.
2
NC No Connect
3
BSA High-Side Driver Boost Pin. Connect a 10nF capacitor from this pin to SWA.
4
INA
Supply Voltage Channel A. The MP2364 operates from a +4.75V to +23V unregulated input.
Input Ceramic Capacitors should be close to this pin.
5
SWA Switch Channel A. This connects the inductor to either INA through M1A or to PGA through M2A.
6
PGA
Power Ground Channel A. This is the Power Ground Connection to the input capacitor
ground.
Signal Ground Channel A. This pin is the signal ground reference for the regulated output
7
SGA
voltage. For this reason care must be taken in its layout. This node should be placed outside
of the D1 to C1 ground path to prevent switching current spikes from inducing voltage noise
into the part.
Feedback Voltage for Channel B. This pin is the feedback voltage. The output voltage is ratio scaled
8
FBB through a voltage divider, and the center point of the divider is connected to this pin. The voltage is
compared to the on board 0.92V reference.
Compensation Channel B. This is the output of the transconductance error amplifier. A series
9 COMPB RC is placed on this pin for proper control loop compensation. Please refer to more in the
datasheet.
Enable/UVLO Channel B. A voltage greater than 2.62V enables operation. Leave ENB
10
ENB
unconnected for automatic startup. An Under Voltage Lockout (UVLO) function can be
implemented by the addition of a resistor divider from V_IN to GND. For complete low current
shutdown the ENB pin voltage needs to be less than 700mV.
11
SSB
Soft-Start Control for Channel B. 9kΩ output resistance from the pin. Set RC time constant
with external capacitor for soft start ramp time. Ramp Time = 2.2x9kΩxC.
12
BSB High-Side Driver Boost Pin. Connect a 10nF capacitor from this pin to SWB.
13
NC No Connect.
14
INB
Supply Voltage Channel B. The MP2364 operates from a +4.75V to +23V unregulated input.
Input Ceramic Capacitors should be close to this pin.
15 SWB Switch Channel B. This connects the inductor to either INB through M1B or to PGB through M2B.
16
PGB
Power Ground Channel B. This is the Power Ground Connection to the input capacitor
ground.
Signal Ground Channel B. This pin is the signal ground reference for the regulated output
17
SGB
voltage. For this reason care must be taken in its layout. This node should be placed outside
of the D1 to C1 ground path to prevent switching current spikes from inducing voltage noise
into the part.
Feedback Voltage for Channel A. This pin is the feedback voltage. The output voltage is ratio scaled
18
FBA through a voltage divider, and the center point of the divider is connected to this pin. The voltage is
compared to the on board 0.92V reference.
Compensation Channel A. This is the output of the transconductance error amplifier. A series
19 COMPA RC is placed on this pin for proper control loop compensation. Please refer to more in the
datasheet.
Enable/UVLO Channel A. A voltage greater than 2.62V enables operation. Leave ENA
20
ENA
unconnected for automatic startup. An Under Voltage Lockout (UVLO) function can be
implemented by the addition of a resistor divider from V_IN to GND. For complete low current
shutdown the ENA pin voltage needs to be less than 700mV.
MP2364 Rev. 1.4
www.MonolithicPower.com
4
3/22/2006
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