Document
New Features • Monitor Voltages: 5V to 0.9V • Independent Core Voltage Monitor
Preliminary Datasheet
X40010/X40011/X40014/X40015
Dual Voltage Monitor with Integrated CPU Supervisor
FEATURES • Dual voltage detection and reset assertion —Standard reset threshold settings See Selection table on page 2. —Adjust low voltage reset threshold voltages using special programming sequence —Reset signal valid to VCC = 1V —Monitor three voltages or detect power fail • Independent Core Voltage Monitor (V2MON) • Fault detection register • Selectable power on reset timeout (0.05s, 0.2s, 0.4s, 0.8s) • Selectable watchdog timer interval (25ms, 200ms, 1.4s, off) • Low power CMOS —25µA typical standby current, watchdog on —6µA typical standby current, watchdog off • 400kHz 2-wire interface • 2.7V to 5.5V power supply operation • Available packages —8-lead SOIC, TSSOP APPLICATIONS • Communication Equipment —Routers, Hubs, Switches —Disk Arrays, Network Storage • Industrial Systems —Process Control —Intelligent Instrumentation • Computer Systems —Computers —Network Servers DESCRIPTION The X40010/11/14/15 combines power-on reset control, watchdog timer, supply voltage supervision, and secondary voltage supervision, in one package. This combination lowers system cost, reduces board space requirements, and increases reliability. Applying voltage to VCC activates the power on reset circuit which holds RESET/RESET active for a period of time. This allows the power supply and system oscillator to stabilize before the processor can execute code. Low VCC detection circuitry protects the user’s system from low voltage conditions, resetting the system when VCC falls below the minimum VTRIP1 point. RESET/ RESET is active until VCC returns to proper operating level and stabilizes. A second voltage monitor circuit tracks the unregulated supply to provide a power fail warning or monitors different power supply voltage. Three common low voltage combinations are available, however, Xicor’s unique circuits allows the
BLOCK DIAGRAM
Watchdog Timer and Reset Logic
SDA
Data Register Command Decode Test & Control Logic Threshold Reset Logic
Fault Detection Register Status Register
WDO
SCL
VCC (V1MON)
+ User Programmable VTRIP1 User Programmable VTRIP2 + V2MON VCC
Power on, Low Voltage Reset Generation
RESET X40010/14 RESET X40011/15
V2MON
V2FAIL
*X40010/11 = V2MON* X40014/15 = VCC
REV 1.3.4 7/12/02
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Characteristics subject to change without notice.
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X40010/X40011/X40014/X40015 – Preliminary
threshold for either voltage monitor to be reprogrammed to meet special needs or to fine-tune the threshold for applications requiring higher precision. The Watchdog Timer provides an independent protection mechanism for microcontrollers. When the microcontroller fails to restart a timer within a selectable time out interval, the device activates the WDO signal. The user selects the interval from three preset values. Once selected, the interval does not change, even after cycling the power. The device features a 2-wire interface and software protocol allowing operation on an I2C® bus.
Dual Voltage Monitors Device
X40010/11 -A -B -C X40014/15 -A -B -C
Expected System Voltages
5V; 3V or 3.3V 5V; 3V 3V; 3.3V; 1.8V 3V; 3.3V; 1.5V 3V; 1.5V 3V or 3.3V; 1.1 or 1.2V
Vtrip1(V)
2.0–4.75* 4.55–4.65* 4.35–4.45* 2.85–2.95* 2.0–4.75* 2.85–2.95* 2.55–2.65* 2.85–2.95*
Vtrip2(V)
1.70–4.75 2.85–2.95 2.55–2.65 1.65–1.75 0.90–3.50* 1.25–1.35* 1.25–1.35* 0.95–1.05*
POR (system)
RESET = X40010 RESET = X40011
RESET = X40014 RESET = X40015
*Voltage monitor requires VCC to operation. Others are independent of VCC.
PIN CONFIGURATION
X40010/14, X40011/15 8-Pin SOIC V2FAIL V2MON RESET/RESET VSS 1 2 3 4 8 7 6 5 VCC WDO SCL SDA WDO VCC V2FAIL V2MON X40010/14, X40011/15 8-Pin TSSOP 1 2 3 4 8 7 6 5 SCL SDA VSS RESET/RESET
PIN DESCRIPTION Pin SOIC TSSOP Name
1 2 3 4
Function
3
5
4
6
V2FAIL V2 Voltage Fail Output. This open drain output goes LOW when V2MON is less than VTRIP2 and goes HIGH when V2MON exceeds VTRIP2. There is no power up reset delay circuitry on this pin. V2MON V2 Voltage Monitor Input. When the V2MON input is less than the VTRIP2 voltage, V2FAIL goes LOW. This input can monitor an unregulated power supply with an external resistor divider or can monitor a second power supply with no external components. Connect V2MON to VSS or VCC when not used.The V2MON comparator is supplied by V2MON (X40010/11) or by VCC Input (X40014/15). RESET/ RESET Output. (X40011/15) This is an active LOW, open drain output which goes active whenRESET ever VCC falls below VTRIP1. It will remain active until VCC rises above VTRIP1 and for the tPURST thereafter. RESET Output. (X40010/14) This is an active HIGH CMOS output which goes active whenever VCC falls below VTRIP1. It will remain active until VCC rises above VTRIP1 and for the tPURST thereafter. VSS Ground
REV 1.3.4 7/12/02
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Characteristics subject to change without notice.
2 of 25.