Datasheet LTM4600 (Analog Devices) - 7

LTM4600
pin FuncTions (See Package Description for Pin Assignment) VIN (Bank 1):
Power Input Pins. Apply input voltage be-
SGND (Pin D23):
Signal Ground Pin. All small-signal tween these pins and PGND pins. Recommend placing components should connect to this ground, which in turn input decoupling capacitance directly between VIN pins connects to PGND at one point. and PGND pins.
RUN/SS (Pin F23):
Run and Soft-Start Control. Forcing
fADJ (Pin A15):
A 110k resistor from VIN to this pin sets this pin below 0.8V will shut down the power supply. the one-shot timer current, thereby setting the switching Inside the power module, there is a 1000pF capacitor frequency. The LTM4600 switching frequency is typically which provides approximately 0.7ms soft-start time with 850kHz. An external resistor to ground can be selected to 200µF output capacitance. Additional soft-start time can reduce the one-shot timer current, thus lower the switching be achieved by adding additional capacitance between the frequency to accommodate a higher duty cycle step down RUN/SS and SGND pins. The internal short-circuit latchoff requirement. See the applications section. can be disabled by adding a resistor between this pin and
SV
the VIN pin. This pull-up resistor must supply a minimum
IN (Pin A17):
Supply Pin for Internal PWM Controller. Leave this pin open or add additional decoupling capacitance. 5µA pull up current. The RUN/SS pin has an internal 6V Zener to ground.
EXTVCC (Pin A19):
External 5V supply pin for controller. If left open or grounded, the internal 5V linear regulator will
FCB (Pin G23):
Forced Continuous Input. Grounding this power the controller and MOSFET drivers. For high input pin enables forced continuous mode operation regardless voltage applications, connecting this pin to an external of load conditions. Tying this pin above 0.63V enables 5V will reduce the power loss in the power module. The discontinuous conduction mode to achieve high efficiency EXTV operation at light loads. There is an internal 4.75K resistor CC voltage should never be higher than VIN. between the FCB and SGND pins.
VOSET (Pin A21):
The Negative Input of The Error Amplifier. Internally, this pin is connected to V
PGOOD (Pin J23):
Output Voltage Power Good Indicator. OUT with a 100k preci- sion resistor. Different output voltages can be programmed When the output voltage is within 10% of the nominal with additional resistors between the V voltage, the PGOOD is open drain output. Otherwise, this OSET and SGND pins. pin is pulled to ground.
COMP (Pin B23):
Current Control Threshold and Error Amplifier Compensation Point. The current comparator
PGND (Bank 2):
Power ground pins for both input and threshold increases with this control voltage. The voltage output returns. ranges from 0V to 2.4V with 0.8V corresponding to zero
VOUT (Bank 3):
Power Output Pins. Apply output load sense voltage (zero current). between these pins and PGND pins. Recommend placing High Frequency output decoupling capacitance directly between these pins and PGND pins. TOP VIEW V CC IN EXT V OSET f ADJ SV 2 3 4 5 6 7 16 17 18 19 A 1 20 B COMP 9 10 11 C VIN 8 21 BANK 1 D SGND 13 14 15 E 12 22 F RUN/SS 25 23 26 27 28 29 30 31 G FCB H 32 24 33 34 35 36 37 38 J PGOOD K PGND 39 40 41 42 43 44 45 46 47 48 49 L BANK 2 50 51 52 53 54 55 56 57 58 59 60 M 61 62 63 64 65 66 67 68 69 70 71 N 72 73 74 75 76 77 78 79 80 81 82 P VOUT 83 84 85 86 87 88 89 90 91 92 93 BANK 3 R 94 95 96 97 98 99 100 101 102 103 104 T 1 3 5 7 9 11 13 15 17 19 21 23 2 4 6 8 10 12 14 16 18 20 22 4600 PN01 4600fd For more information www.linear.com/LTM4600 7 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Simplified Block Diagram Decoupling Requirements Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts