UL 1950/60950 validation

AN1011

4/11

Doc ID 6254 Rev 4

UL 1950/60950 validation

All ZEROPOWER, TIMEKEEPER and RTC devices are recognized by the Underwriters

Laboratory Inc. UL 1950/60950 specification. The conditions for acceptance under this

include the following:

1.

That the devices are intended for use as components where the replacement of the

battery can be performed by the operator or a trained technician.

2.

That the devices are intended for use as components in low voltage, isolated,

secondary circuits; where the case temperature does not exceed 100 °C, and the

3.

That the devices are intended to be mounted on a printed wiring board, flame rated to a

minimum of 94 V-1.

4.

That the devices are provided with an appropriate on-chip, reverse current protection

circuit. (See Figure 3 for the circuit diagram.)

Figure 3.

Battery control circuit

1.

2.

Depending on the device, switchover will be a function of battery voltage or set by a fixed reference.

AI02520

VSO

VCC

P

BATTERY

RA

(1)

RB

(1)

VSO

P

INTERNAL VCC

(ON when VCC is below

(OFF when VCC is below

the switchover voltage)

(2)