Rainbow Electronics MAX5068 - Manual (Page 8)

MAX5068
High-Frequency, Current-Mode PWM Controller
with Accurate Programmable Oscillator
8 _______________________________________________________________________________________
Pin Description
PIN
MAX5068A
MAX5068B MAX5068C
MAX5068E
MAX5068D
MAX5068F
NAME FUNCTION
1 1 1 RT
Oscillator-Timing Resistor Connection. Connect a resistor from RT to AGND
to set the internal oscillator frequency.
2 2 — SYNC
External-Clock Sync Input. Connect SYNC to AGND when not using an
external clock.
3 — 2 HYST Programmable Hysteresis Input
— 3 3 SCOMP
Slope-Compensation Capacitor Input. Connect a capacitor to AGND to set
the slope compensation.
4 4 4 DT
Dead-Time Adjustment. Connect a resistor from DT to AGND to adjust NDRV
dead time. Connect to REG5 for maximum duty cycle.
5 5 5 UVLO/EN
Externally Programmable Undervoltage Lockout. UVLO/EN programs the
input start voltage. Drive UVLO/EN to AGND to disable the output.
6 6 6 FB Error-Amplifier Inverting Input
7 7 7 COMP Error-Amplifier Compensation Output
8 8 8 FLTINT
Fault-Integration Input. A capacitor connected to FLTINT charges with an
internal 60µA current source during repeated current-limit events. Switching
terminates when V
FLTINT reaches 2.9V. An external resistor connected in
parallel discharges the capacitor. Switching resumes when V FLTINT drops to
1.6V.
9 9 9 CS Current-Sense Resistor Connection
10, 12 10, 12 10, 12 AGND Analog Ground. Connect to PGND through a ground plane.
11 11 11 PGND Power Ground. Connect to AGND through a ground plane.
13 13 13 NDRV
G ate- D r i ver O utp ut. C onnect the N D RV outp ut to the g ate of the exter nal
N - channel FE T.
14 14 14 V CC
9V Linear-Regulator Output. Decouple V CC with a minimum 1µF ceramic
capacitor to the AGND plane; also internally connected to the FET driver.
15 15 15 IN
Power-Supply Input. IN provides power for all internal circuitry. Decouple IN
with a minimum 0.1µF ceramic capacitor to AGND (see the Typical
Operating Circuit).
16 16 16 REG5
5V Linear-Regulator Output. Decouple to AGND with a 0.1µF ceramic
capacitor.
EP EP EP PAD Exposed Pad. Connect to GND.