Rainbow Electronics MAX1585 - Manual (Page 11)

MAX1584/MAX1585
5-Channel Slim DSC Power Supplies
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Pin Description (continued)
PIN NAME FUNCTION
16 AUX1OK
Open-Drain Power-OK Signal for AUX1 Controller. AUX1OK is low when the AUX1 controller has
successfully completed soft-start. This pin is high impedance in shutdown, overload, and thermal limit.
17 SDOK
Open-Drain Power-OK Signal for Step-Down Converter. SDOK is low when the step-down has successfully
completed soft-start. This pin is high impedance in shutdown, overload, and thermal limit.
18 SCF
Short-Circuit Flag, Active-Low, Open-Drain Output. SCF is high impedance when overload protection
occurs and during startup. SCF can drive high-side PFET switches connected to one or more outputs to
completely disconnect the load when the channel turns off in response to a logic command or an
overload. See the Status Outputs (
SDOK , AUX1OK , SCF) section.
19 OSC
Oscillator Control. Connect a timing capacitor from OSC to GND and a timing resistor from OSC to PVSU
(or other DC voltage) to set the oscillator frequency between 100kHz and 1MHz. See the Setting the
Switching Frequency section. This pin is high impedance in shutdown.
20 PGSU
Step-Up Power Ground. Connect all PG_ pins together and to GND with short traces as close to the IC as
possible.
21 LXSU
Step-Up Converter Switching Node. Connect to the inductor of the step-up converter. LXSU is high
impedance in shutdown.
22 PVSU
Power Output of the Step-Up DC-DC Converter. Connect the output filter capacitor from PVSU to PGSU.
PVSU can also power other converter channels. Connect PVSU to PV at the IC.
MAX1585 (AUX2 inverter): The FB2 feedback threshold is 0V.
Connect a resistive voltage-divider from the output voltage to FB2 to
REF to set the output voltage.
23 FB2
AUX2 Controller Feedback Input.
This pin is high impedance in
shutdown.
MAX1584 (AUX2 step-up): The FB2 feedback threshold is 1.25V.
Connect a resistive voltage-divider from the output voltage to FB2 to
GND to set the output voltage.
24 CC2
AUX2 Controller Compensation Node. Connect a series resistor-capacitor from CC2 to GND to
compensate the control loop. CC2 is actively driven to GND in shutdown and thermal limit. See the AUX
Compensation section.
MAX1585 (AUX2 inverter): Connect INDL2 to the external P channel
MOSFET source (typically the battery) to ensure the P channel is
completely off when D2 swings high.
25 INDL2
Voltage Input for the AUX2 Gate
Driver. The voltage at INDL2 sets
the high gate-drive voltage.
MAX1584 (AUX2 step-up): Connect INDL2 to PVSU for optimum
N-channel gate drive.
26 PV IC Power Input. Connect PVSU and PV together.
MAX1585: DL2 drives a PFET in an inverter configuration. In
shutdown, overload, and thermal limit, DL2 is driven high.
27 DL2
AUX2 Controller Gate-Drive
Output. DL2 drives between
INDL2 and GND.
MAX1584: DL2 drives an N-channel FET in a boost/flyback
configuration. In shutdown, overload, and thermal limit, DL2 is driven
low.