HT66F03M View Datasheet(PDF) - Holtek Semiconductor

Part Name

Description

Manufacturer

HT66F03M

1.5V Battery Flash Type 8-Bit MCU with EEPROM & DC-DC Converter

Holtek Semiconductor 

HT68F03M/HT68F04M/HT66F03M/HT66F04M

Functional Description

As these device packages contain multiple internal chips,

for a detailed functional description, users must refer to

the relevant individual datasheets for both the MCU and

the DC-DC Converter. The following table shows which

individual devices are inside each package.

Device

HT68F03M

HT68F04M

HT66F03M

HT66F04M

MCU

HT68F03

HT68F04

HT66F03

HT66F04

DC-DC Converter

HT7730

HT7730

HT7730

HT7730

Multi-chip Internal Devices

Although most of the functional description material will

be located in the individual datasheets, there are some

special considerations which need to be taken into ac-

count when using multi-chip devices. These points will

be mentioned in the hardware and software consider-

ation sections.

Multi-chip Hardware Considerations

As these single-package multi-chip devices are com-

posed of an individual MCU and DC-DC converter

chips, using them together requires the user to take care

of some special points.

· Absolute Maximum Ratings

The Absolute Maximum Ratings for the two individual

chips must be checked for discrepancies and the nec-

essary care taken in device handling and usage.

· Power Supply

Examination of the block diagram will reveal that the

DC-DC Converter Ground pin, GND, has no internal

connection to the MCU Ground pin, VSS. For this rea-

son these two pins must be connected externally. The

DC-DC Converter output pin, VOUT is also not con-

nected to the MCU power supply pin, VDD, so these

two pins should also be connected together exter-

nally. If the DC-DC Converter is used to power the

MCU, then the MCU will always have a power supply

of 3V, so care must be taken to only consult the MCU

characteristics specified at this power supply voltage.

If required, the MCU can be supplied directly on its

VDD pin by an external power source if the DC-DC

converter is not used.

When calculating the total current consumption of the

device, the internal DC specifications of the two inter-

nal chips must be consulted and the individual cur-

rents added together.

As the MCU power supply may be supplied by the

DC-DC Converter it is important to note that if the

MCU is powered down or placed into a low power

mode to conserve power, that the DC-DC Converter

will continue running and will consume a certain

amount of power. The DC-DC Converter can of

course be powered down by pulling its CE pin low,

however as its output voltage falls toward zero, the

MCU will experience a reset. The CE pin must there-

fore be held low for sufficient time to allow the VOUT

voltage to fall to a level where the MCU will be prop-

erly reset before being powered up again.

Multi-chip Programming Considerations

As there are no internal signal connections between the

two internal chips there are no real programming con-

siderations for these devices. It is only necessary to

realise that if the MCU is switched into any of its low

power modes or executes the HALT instruction by the

application program to reduce power consumption, that

the DC-DC Converter will continue operating and there-

fore contribute to the overall power consumption. The

DC-DC Converter can only be powered-down manually

using its CE pin and if this is done the MCU will be reset.

Rev. 1.10

7

May 24, 2010

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