MAX3320A/B/L/T 19-1253 Rev 0 8/97 3V to 5.5V, up to 250kbps True RS-232 Transceiver with 4A AutoShutdown Plus and Power-On Reset General Description Features The MAX3320 combines a microprocessor (P) super- Precise Monitoring of 5V and 3.3V Power- visory circuit with an RS-232 transceiver. The power-on Supply Voltages: reset performs a single function: it asserts a reset signal 100ms (min) Power-On RESET Pulse Width whenever the V supply voltage declines below a pre- CC Power-Supply Transient Immunity set threshold, staying asserted for at least 100ms after Guaranteed RESET Valid to V = 1V CC V rises above the reset threshold. The MAX3320 has CC an active-low RESET output, which is guaranteed to be in 4A Supply Current Achieved with the correct state for V down to 1V. The reset compara- CC AutoShutdown Plus tor is designed to ignore fast transients on V . Reset CC Receivers Always Active thresholds suitable for operation with a variety of supply voltages are available. Power-On Reset Always Active The MAX3320 transceivers have a proprietary low- 4A Low-Power Shutdown dropout transmitter output stage, enabling true RS-232 performance with a dual charge pump powered from a 250kbps Guaranteed Data Rate +3V to +5.5V supply. The device requires only four small 0.1F external charge-pump capacitors, and is guaranteed to run at data rates of up to 250kbps. It comes in the space-saving 20-pin SSOP package. Applications Ordering Information Palmtop Computers PART* TEMP. RANGE PIN-PACKAGE Portable/Battery-Powered Equipment MAX3320 CAP 0C to +70C 20 SSOP Hand-Held Equipment MAX3320 EAP -40C to +85C 20 SSOP Peripherals * This part offers a choice of reset threshold voltage. From the table below, select the suffix corresponding to the desired Printers threshold and insert it into the blank to complete the part number. Pin Configuration RESET THRESHOLD SUFFIX (V) A 4.25 TOP VIEW B 2.85 V+ 1 20 C1+ L 4.63 C2+ 2 19 V CC T 3.08 C2- 3 18 C1- V- 4 17 GND MAX3320 MAXxxx T1IN 5 16 T1OUT T2IN 6 15 T2OUT Typical Operating Circuit appears at end of data sheet. R1OUT 7 14 R1IN R2OUT 8 13 R2IN INVALID 9 12 FORCEON RESET 10 11 FORCEOFF SSOP AutoShutdown Plus is a trademark of Maxim Integrated Products. Maxim Integrated Products 1 For free samples & the latest literature: 3V to 5.5V, up to 250kbps True RS-232 Transceiver with 4A AutoShutdown Plus and Power-On Reset ABSOLUTE MAXIMUM RATINGS V .............................................................................-0.3V to 6V Short-Circuit Duration CC V+ (Note 1) .................................................................-0.3V to 7V T OUT....................................................................Continuous V- (Note 1)...................................................................0.3V to -7V Continuous Power Dissipation (T = +70C) A V+ + V- (Note 1) ...................................................................13V SSOP (derate 8.00mW/C above +70C) ....................640mW Input Voltages Operating Temperature Ranges T IN, FORCEOFF, FORCEON................................-0.3V to 6V MAX3320 CAP ...................................................0C to +70C R IN.................................................................................25V MAX3320 EAP ................................................-40C to +85C Output Voltages Storage Temperature Range .............................-65C to +160C T OUT ..........................................................................13.2V Lead Temperature (soldering, 10sec) .............................+300C R OUT, INVALID, RESET.......................-0.3V to (V + 0.3V) CC Note 1: V+ and V- can have a magnitude of +7V (max), but their absolute difference cannot exceed +13V. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = 3V to 5.5V, C1C4 = 0.1F (tested at 3.3V 10%), C1 = 0.047F, C2C4 = 0.33F (tested at 5V 10%), T = T to T , CC A MIN MAX unless otherwise noted. Typical values are at T = +25C.) A PARAMETER CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS Power-Supply Current No load, V = 3.3V or 5V, T = +25C 0.45 1.0 mA CC A Shutdown Supply Current FORCEOFF = GND, T = +25C 4.0 10 A A AutoShutdown Plus All R IN unconnected, FORCEON = GND, 4.0 10 A Supply Current FORCEOFF = V , all T IN = V or GND, T = +25C CC CC A LOGIC INPUTS AND RECEIVER OUTPUTS Input Logic Threshold Low 0.8 V T IN, FORCEON, FORCEOFF V = 3.3V 2.0 T IN, FORCEON, CC Input Logic Threshold High V FORCEOFF V = 5V 2.4 CC Input Leakage Current T IN, FORCEON, FORCEOFF 0.01 1.0 A Input Hysteresis 250 mV T IN, FORCEON, FORCEOFF Output Voltage Low I = 1.6mA 0.4 V OUT V - V CC CC - Output Voltage High I = -1mA V OUT 0.6 0.1 RECEIVER INPUTS Input Voltage Range -25 25 V V = 3.3V 0.6 1.2 CC Input Threshold Low V V = 5V 0.8 1.5 CC V = 3.3V 1.5 2.4 CC Input Threshold High V V = 5V 1.8 2.4 CC Input Hysteresis 0.3 V kW Input Resistance T = +25C 3 5 7 A INVALID OUTPUT Figure 3, positive threshold 2.7 Receiver Input Threshold to V INVALID Output High Figure 3, negative threshold -2.7 Receiver Input Threshold to Figure 3 -0.3 0.3 V INVALID Output Low INVALID Output Voltage Low I = 1.6mA 0.4 V OUT 2 MAX3320A/B/L/T