Skip to main content Skip to first level navigation

RICOH imagine. change.

RICOH ELECTRONIC DEVICES CO., LTD.

Skip to main content First level navigation Menu
Main content

Rx5C348
4-wire Serial Interface Real Time Clock (RTC)

Product Specifications

The Rx5C348 are CMOS real-time clock ICs connected to the CPU by four signal lines, CE, SCLK, SI, SO, and configured to perform serial transmission of time and calendar data to the CPU. The periodic interrupt circuit is configured to generate interrupt signals with six selectable interrupts ranging from 0.5 seconds to 1 month. The 2 alarm interrupt circuits generate interrupt signals at preset times. As the oscillation circuit is driven under constant voltage, fluctuation of the oscillator frequency due to supply voltage is small, and the time keeping current is small (TYP. 0.35 µA at 3V: Rx5C348A, TYP. 0.55 µA at 3V: Rx5C348B). The oscillation halt sensing circuit can be used to judge the validity of internal data in such events as power-on; The supply voltage monitoring circuit is configured to record a drop in supply voltage below two selectable supply voltage monitoring threshold settings. The 32.768 kHz clock output function (N-channel open drain output) is intended to output sub-clock pulses for the external microcomputer. The 32-kHz clock circuit can be disabled by certain register settings for the Rx5C348A but cannot be disabled by any register settings for the Rx5C348B. The oscillation adjustment circuit is intended to adjust time counts with high precision by correcting deviations in the oscillation frequency of the crystal oscillator. SSOP10 and SSOP10G packages are available.

FEATURES

Timekeeping supply voltage 1.45 to 5.5 V
Supply Current Rx5C348A: Typ. 0.35 µA (VDD=3V)
Rx5C348B: Typ. 0.55 µA (VDD=3V)
Connected to the CPU Four signal lines (CE, SCLK, SI, and SO), Maximum clock frequency of 2 MHz (with VDD = 5V)
Functions Time counters (counting hours, minutes, and seconds) and calendar counters (counting years, months, days,and weeks) (in BCD format)
Interrupt circuit configured to generate interrupt signals (with interrupts ranging from 0.5 seconds to 1 month) to the CPU and provided with an interrupt flag and an interrupt halt
2 alarm interrupt circuits (Alarm_W for week, hour, and minute alarm settings and Alarm_D for hour and minute alarm settings)
Oscillation halt sensing circuit which can be used to judge the validity of internal data
Supply voltage monitoring circuit with two supply voltage monitoring threshold settings
Automatic identification of leap years up to the year 2099
Selectable 12-hour and 24-hour mode settings
Clock Output 32-kHz (Nch. open drain output)
The Rx5C348A is designed to disable 32-kHz clock output in response to a command from the host computer and the Rx5C348B is designed to keep 32-kHz output enabled.
Built-in Circuits Oscillation stabilization capacitors (CG and CD)
High precision oscillation adjustment
Packages SSOP10G, SSOP10

PIN DESCRIPTION

SSOP10G

SSOP10G2.9 mm × 4.0 mm
1 32KOUT
2 SCLK
3 SO
4 SI
5 VSS
6 INTR
7 CE
8 OSCOUT
9 OSCIN
10 VDD

SSOP10

SSOP103.5 mm × 6.4 mm
1 32KOUT
2 SCLK
3 SO
4 SI
5 VSS
6 INTR
7 CE
8 OSCOUT
9 OSCIN
10 VDD

Rx5C348 for Consumer

APPLICATIONS

  • Home appliances such as refrigerators, rice cookers, and electric pots
  • Digital appliances such as laptops, digital TVs, DSCs, camcorders, mobile phones, and private LAN system
  • Office appliances such as copiers, printers, facsimiles, scanners, and projectors

SELECTION GUIDE

Product Name   Package Quantity per Reel
RV5C348$-E2-# Consumter SSOP10G 2,000
RS5C348A-E2-# Consumter SSOP10 2,000
  • $ … Designation of the function of 32-kHz clock output
    A: Controllable by command
    B: Keeping output enabled
  • # … Designation of the lead plating
    F: Lead free plating
    FB: Sn-Bi plating

DOCUMENT/CONTACT

Purchase

Technical Support

Package *1 Reliability *2
SSOP10G RV5C348A/B
SSOP10 RS5C348A

*1: The package file includes package dimensions, taping specifications, taping reels dimensions, and land pattern (foot pattern).
*2: Reliability file includes a reliability test report and a reflow profile.

Inquiry about products

Technical Support

Inquiries (SSL Form)

Inquiry about business

Purchase, Request for Samples and Documents

Distributors

Sample Online

Online Distributors