Figure 6a shows the transmitter output voltages under

increasing load current at +3.0V. Figure 6b shows a

typical mouse connection using the MAX3241E.

High Data Rates

The MAX3222E/MAX3232E/MAX3237E/MAX3241E/

MAX3246E maintain the RS-232 ±5V minimum transmit-

ter output voltage even at high data rates. Figure 7

shows a transmitter loopback test circuit. Figure 8

shows a loopback test result at 120kbps, and Figure 9

shows the same test at 250kbps. For Figure 8, all trans-

mitters were driven simultaneously at 120kbps into RS-

232 loads in parallel with 1000pF. For Figure 9, a single

transmitter was driven at 250kbps, and all transmitters

were loaded with an RS-232 receiver in parallel with

1000pF.

The MAX3237E maintains the RS-232 ±5.0V minimum

transmitter output voltage at data rates up to 1Mbps.

Figure 10 shows a loopback test result at 1Mbps with

loaded with an RS-232 receiver in parallel with 250pF.

Interconnection with 3V and 5V Logic

The MAX3222E/MAX3232E/MAX3237E/MAX3241E/

MAX3246E can directly interface with various 5V logic

families, including ACT and HCT CMOS. See Table 3

for more information on possible combinations of inter-

connections.

UCSP Reliability

The UCSP represents a unique packaging form factor

that may not perform equally to a packaged product

through traditional mechanical reliability tests. UCSP

reliability is integrally linked to the user’s assembly

methods, circuit board material, and usage environ-

ment. The user should closely review these areas when

considering use of a UCSP package. Performance

through Operating Life Test and Moisture Resistance

remains uncompromised as the wafer-fabrication

process primarily determines it.

Mechanical stress performance is a greater considera-

tion for a UCSP package. UCSPs are attached through

direct solder contact to the user’s PC board, foregoing

the inherent stress relief of a packaged product lead

frame. Solder joint contact integrity must be consid-

ered. Table 4 shows the testing done to characterize

the UCSP reliability performance. In conclusion, the

UCSP is capable of performing reliably through envi-

ronmental stresses as indicated by the results in the

table. Additional usage data and recommendations are

detailed in the UCSP application note, which can be

found on Maxim’s website at www.maxim-ic.com.

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,

Up to 1Mbps, True RS-232 Transceivers

14

______________________________________________________________________________________

Table 4. Reliability Test Data

TEST

CONDITIONS

DURATION

FAILURES PER

SAMPLE SIZE

Temperature Cycle

150 cycles,

900 cycles

0/10,

0/200

Operating Life

240 hours

0/10

Moisture Resistance

240 hours

0/10

Low-Temperature Storage

240 hours

0/10

Low-Temperature Operational

24 hours

0/10

Solderability

8-hour steam age

—

0/15

ESD

±15kV, Human Body Model

—

0/5

High-Temperature Operating

Life

168 hours

0/45