Key Application Considerations; Topswitch-Hx Vs.topswitch-Gx - Power integrations TOPSwitch-HX Series Manual

Key Application Considerations

TOPSwitch-HX vs. TOPSwitch-GX
Table 4 compares the features and performance differences
between TOPSwitch-HX and TOPSwitch-GX. Many of the new
TOPSwitch-HX vs. TOPSwitch-GX
Function
EcoSmart
Output Overvoltage
Protection (OVP)
Line Feed-Forward with Duty
Cycle Reduction
Switching Frequency DIP-8
Package
Lowest MOSFET On
Resistance in DIP-8 Package
I 2 f Trimming
Auto-restart Duty Cycle
Frequency Jitter
Thermal Shutdown
External Current Limit
Line UV Detection Threshold
Soft-Start
Table 4. Comparison Between TOPSwitch-GX and TOPSwitch-HX.
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TOPSwitch-GX TOPSwitch-HX
Linear frequency reduction to Multi-mode operation with
30 kHz (@ 132 kHz) for linear frequency reduction to
duty cycles < 10% 30 kHz (@ 132 kHz) and
multi-cycle modulation
(virtually no audible noise)
Not available User programmable primary
or secondary hysteretic or
latching OVP
Linear reduction Dual slope reduction with
lower, more accurate onset
point
132 kHz 66 kHz
3.0 W (TOP246P) 1.8 W (TOP258P)
Not available -10% / +20%
5.6% 2%
±4 kHz @ 132 kHz ±5 kHz @ 132 kHz
±2 kHz @ 66 kHz ±2.5 kHz @ 66 kHz
130 °C to 150 °C 135 °C to 150 °C
30%-100% of I 30%-100% of I
LIMIT
trim at 0.7 × I
50 mA (2 MW sense 25 mA (4 MW sense
impedance) impedance)
10 ms duty cycle and current 17 ms sweep through
limit ramp multi-mode characteristic
features eliminate the need for additional discrete components.
Other features increase the robustness of design, allowing cost
savings in the transformer and other power components.
TOPSwitch-HX Advantages
Improved efficiency over load (e.g. at 25% load
•
point)
Improved standby efficiency
•
Improved no-load consumption
•
Protects power supply output during open loop fault
•
Maximum design flexibility
•
Improved line ripple rejection
•
Smaller DC bus capacitor
•
Increased output power for given MOSFET size due
•
to higher efficiency
Increased output power in designs without external
•
heat sink
Increased output power for given core size
•
Reduced over-load power
•
Reduced delivered average output power during
•
open loop faults
Reduced EMI filter cost
•
Increased design margin
•
, additional
Reduced tolerances when current limit is set
•
LIMIT
externally
LIMIT
Reduced dissipation for lower no-load consumption
•
Reduced peak current and voltage component
•
stress at startup
Smooth output voltage rise
•
TOP252-262
25
Rev. J 08/16