ZXSC440X8TA Diodes Zetex, ZXSC440X8TA Datasheet - Page 9

• Manufacturer Part Number: ZXSC440X8TA
• Description: IC PHOTOFLASH CHARGER 8MSOP
• Manufacturer: Diodes Zetex

Specifications of ZXSC440X8TA

• Applications: Photoflash Capacitor Charger
• Current - Supply: 220µA
• Voltage - Supply: 1.8 V ~ 8 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ZXSC440X8TR

Layout issues
Layout is critical for the circuit to function in the most
efficient manner in terms of electrical efficiency,
thermal considerations and noise.
For 'step-up converters' there are four main current
loops, the input loop, power-switch loop, rectifier loop
and output loop. The supply charging the input
capacitor forms the input loop. The power-switch loop
is defined when Q1 is 'on', current flows from the input
through the transformer primary, Q1, R
ground. When Q1 is 'off', the energy stored in the
transformer is transferred from the secondary to the
output capacitor and load via D1, forming the rectifier
loop. The output loop is formed by the output capacitor
supplying the load when Q1 is switched back off.
ISSUE 1 - JANUARY 2005
SENSE
and to
9
To optimize for best performance each of these loops
kept separate from each other and interconnected with
short, thick traces thus minimizing parasitic
inductance, capacitance and resistance. Also the
R
trace length, between emitter lead of Q1 and ground,
again minimizing stray parasitics.
SENSE
resistor should be connected, with minimum
S E M I C O N D U C T O R S
ZXSC440