Rainbow Electronics MAX5069 - Manual (Page 4)

MAX5069
High-Frequency, Current-Mode PWM Controller
with Accurate Oscillator and Dual FET Drivers
4 _______________________________________________________________________________________
Note 1: The MAX5069 is 100% tested at T
A
= +25°C. All limits over temperature are guaranteed by design.
Note 2: The MAX5069A/B are intended for use in universal-input power supplies. The internal clamp circuit is used to prevent the
bootstrap capacitor (C1 in Figure 1) from charging to a voltage beyond the absolute maximum rating of the device when
UVLO/EN is low. The maximum current to V
IN (hence to clamp) when UVLO is low (device is in shutdown) must be external-
ly limited to 2mA. Clamp currents higher than 2mA may result in clamp voltages higher than 30V, thus exceeding the
absolute maximum rating for V
IN . For the MAX5069C/D, do not exceed the 24V maximum operating voltage of the device.
Note 3: Reference voltage (V
REF ) is measured with FB connected to COMP (see the Functional Diagram).
Note 4: The SYNC frequency must be at least 25% higher than the programmed oscillator frequency.
Note 5: The internal oscillator clock cycle.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
NDRV_ Switching Frequency f SW f SW = 10 11 / (2 x R RT ) 25 1250 kHz
RT Voltage V RT 40kΩ < R RT < 500kΩ 2.0 V
f OSC ≤ 500kHz -2.5 +2.5
T
A
= +25°C
f OSC > 500kHz -4 +4
f OSC ≤ 500kHz -4.5 +4.5
Oscillator Accuracy
T A = -40°C to +125°C
f OSC > 500kHz -6 +6
%
Maximum Duty Cycle D MAX DT connected to REG5 100 %
DEAD-TIME CONTROL (DT)
Dead Time t
DT
R
DT
= 24.9kΩ 60 ns
Dead-Time Disable Voltage V DT_DISABLE
V REG5 -
0.5V
V
Dead-Time Regulation Voltage V DT 1.23 V
INTEGRATING FAULT PROTECTION (FLTINT)
FLTINT Source Current I FLTINT V FLTINT = 0V 60 µA
FLTINT Shutdown Threshold V FLTINT_SD V FLTINT rising 2.8 V
FLTINT Restart Threshold V FLTINT_RS V FLTINT falling 1.6 V
SLOPE COMPENSATION
Slope Compensation V SLOPE C SLOPE = 100pf, RT = 110kΩ 15 mV/µs
Slope-Compensation Range V
SLOPER
0 90 mV/µs
Slope-Compensation Voltage
Range
V SCOMP 0 2.7 V
ELECTRICAL CHARACTERISTICS (continued)
(V IN = +12V for the MAX5069C/D, V IN = +23.6V for the MAX5069A/B at startup, then reduces to +12V, C IN = C REG5 = 0.1µF,
C VCC = 1µF, R RT = 100kΩ, NDRV_ = floating, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.) (Note 1)