16.13.2.
GENERAL DESCRIPTION
The PCF8583 is a clock/calendar circuit based on a 2048-bit static CMOS RAM organised as 256 words by
8 bits. Addresses and data are transferred serially via the two-line bi-directional I
2
C-bus. The built-in word
address register is incremented automatically after each written or read data byte. Address pin A0 is used for
programming the hardware address, allowing the connection of two devices to the bus without additional
hardware. The built-in 32.768 kHz oscillator circuit and the first 8 bytes of the RAM are used for the
clock/calendar and counter functions. The next 8 bytes may be programmed as alarm registers or used as free
RAM space. The remaining 240 bytes are free RAM locations.
SYMBOL PIN DESCRIPTION
OSCI 1 oscillator input, 50 Hz or event-pulse input
OSCO 2 oscillator output
A0 3 address input
V
SS
4 negative supply
SDA 5 serial data line
SCL 6 serial clock line
INT 7 open drain interrupt output (active LOW)
V
DD
8 positive supply
16.14.
MC33260:
16.14.1.
General Features:
-Standard Constant Output Voltage or “Follower Boost” Mode
-Switch Mode Operation: Voltage Mode
-Latching PWM for Cycle–by–Cycle On–Time Control
-Constant On–Time Operation That Saves the Use of an Extra Multiplier
-Totem Pole Output Gate Drive
-Undervoltage Lockout with Hysteresis
-Low Start–Up and Operating Current
-Improved Regulation Block Dynamic Behaviour
-Synchronisation Capability
-Internally Trimmed Reference Current Source
16.14.2.
Safety Features:
-Overvoltage Protection: Output Overvoltage Detection
-Undervoltage Protection: Protection Against Open Loop
-Effective Zero Current Detection
-Accurate and Adjustable Maximum On–Time Limitation
-Overcurrent Protection
-ESD Protection on Each Pin
16.14.3.
LIMITS:
-Vcc MAX voltage 16V
-Gate drive current source=-500mA, sink=500mA
-Input voltage –0.3V to +1.0V
-Operating junction Tempe150 C
16.14.4.
PINNING
Pin1=Feedback input
Pin2=Vcontrol
Pin3=Oscillator capacitor(Ct)
