My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX703CSA
- Part No.:
- MAX703CSA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX703CSA.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,599
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX703CSA from Maxim Integrated is a low-cost microprocessor supervisory circuit in 8-pin SO package, providing active-low reset (4.65V threshold), battery-backup switching, 1.25V power-fail comparator input, and debounced manual reset - used to ensure reliable startup and brownout recovery in +5V μP systems with CMOS RAM backup.
For engineers reviewing the MAX703CSA datasheet, MAX703CSA pinout, MAX703CSA application, or MAX703CSA equivalent, key selection factors include guaranteed RESET assertion down to VCC = 1V, 200ms reset pulse width, 50nA battery-backup quiescent current, and precise switchover hysteresis (40mV) between VCC and VBATT.
Technical Context
The MAX703CSA integrates four core functions: a precision voltage monitor with 4.65V ±150mV reset threshold and 40mV hysteresis; a battery switchover circuit using p-channel MOSFETs (5Ω in VCC mode, 80Ω in VBATT mode); a 1.25V reference-based power-fail comparator with PFI/PFO interface; and TTL/CMOS-compatible MR input with internal 250µA pullup.
It operates across 0°C to +70°C, supports VCC = 4.75V–5.5V and VBATT = 2.8V, asserts RESET low during power-up/down/brownout, and guarantees valid RESET output even as VCC falls to 1V - enabling robust reset signaling in degraded supply conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65V ±150mV - ensures reset activation before +5V supply drops below safe μP operating margin |
| Reset Pulse Width | 200ms typical - provides sufficient time for μP initialization and peripheral stabilization after power recovery |
| Supply Current | 200–350µA at VCC = 4.75–5.5V - enables low-power system monitoring without burdening main supply |
| Battery-Backup Current | 50nA typical - extends lithium battery life beyond 10 years in standby memory retention applications |
| Power-Fail Input Threshold | 1.25V ±50mV - allows accurate detection of unregulated supply droop via external resistor divider |
| VBATT Switchover Hysteresis | 40mV - prevents oscillatory switching during slow VCC decay near VBATT voltage |
| RESET Valid Down To | VCC = 1V - maintains deterministic reset state even during deep brownout or controlled power ramp-down |
Pinout & Package
MAX703CSA uses an 8-pin SO (Small Outline) package with standard JEDEC MS-012AC footprint (S8+2 code), 1.27mm pitch, and RoHS-compliant lead-free finish (denoted by "+" suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VOUT | RAM supply output | Switches between VCC (via 5Ω p-MOSFET) and VBATT (via 80Ω p-MOSFET) based on reset threshold crossing and switchover hysteresis |
| 2 - VCC | +5V main supply input | Primary power source; powers internal circuitry and drives VOUT when above 4.65V; monitored for reset generation |
| 3 - GND | Ground reference | Common return path for all analog and digital functions; substrate connection point |
| 4 - PFI | Power-fail comparator input | High-impedance (±25nA) node compared to 1.25V reference; used to monitor auxiliary supplies or unregulated rails |
| 5 - PFO | Power-fail comparator output | Open-drain active-low output; sinks current when PFI < 1.25V; disabled in battery-backup mode |
| 6 - MR | Manual reset input | TTL/CMOS-compatible active-low input with 250µA internal pullup; debounced by 200ms reset timer |
| 7 - RESET | Supervisory reset output | Active-low open-drain output; asserted low during power-up, brownout, or MR activation; guaranteed to sink 3.2mA at VOL ≤ 0.4V |
| 8 - VBATT | Battery backup input | Accepts 2.8–4.8V lithium or supercap source; powers internal circuitry and VOUT when VCC fails |
Key Features
| Feature | Design Value |
|---|---|
| Guaranteed RESET assertion to VCC = 1V | Ensures deterministic reset behavior during deep brownout or controlled power-down sequences where VCC decays below 2V |
| 40mV VBATT/VCC switchover hysteresis | Eliminates chattering during slow supply collapse, preventing repeated RAM supply toggling that could corrupt data |
| 50nA quiescent current in battery-backup mode | Enables >10-year lithium battery life for static RAM retention in industrial controllers and embedded instruments |
| Debounced MR input with 200ms minimum pulse | Removes need for external RC debounce circuitry while ensuring clean, single-pulse reset initiation from mechanical switches |
| 1.25V precision PFI reference | Supports accurate power-fail warning for unregulated supplies via simple resistor dividers, with minimal component count |
Applications
| Industrial PLC Controllers | Medical Instrumentation |
|---|---|
Use Scenario: Maintaining volatile configuration and calibration data in programmable logic controllers during AC mains interruption. IC Role / Device Role / Timing Role: Supervisory circuit providing battery-backed VOUT to SRAM and asserting RESET to halt CPU execution until stable +5V resumes. Use Value: Prevents loss of operational parameters and ensures deterministic restart after brief power glitches without requiring nonvolatile storage writes. | Use Scenario: Preserving real-time patient monitoring state and sensor calibration in portable diagnostic devices during battery swap. IC Role / Device Role / Timing Role: Automatic switchover from main supply to coin-cell battery upon VCC drop, with 200ms RESET hold to freeze processor state. Use Value: Enables hot-swap capability of primary battery without interrupting critical measurement cycles or triggering unsafe device resets. |
| Embedded Data Loggers | Point-of-Sale Terminals |
Use Scenario: Safeguarding timestamped sensor readings and firmware update status during unexpected power loss in remote environmental monitors. IC Role / Device Role / Timing Role: Voltage monitor generating early power-fail warning (via PFO) and hard reset (via RESET) to initiate graceful shutdown and data commit. Use Value: Reduces risk of filesystem corruption by allowing µP to flush buffers and set clean shutdown flags before VCC collapses below 4.65V. | Use Scenario: Securing transaction logs and encryption keys in retail terminals during grid instability or UPS transition delays. IC Role / Device Role / Timing Role: Dual-role supervisor: asserting RESET during brownout and switching VOUT to backup battery to retain SRAM contents across power gaps. Use Value: Meets PCI PTS requirements for secure data retention during power interruptions without adding discrete backup diodes or regulators. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX704CSA | 4.40V reset threshold (vs. 4.65V), identical pinout, timing, and features | Suitable for systems with tighter +5V tolerance (±10%) or lower-voltage μPs requiring earlier reset assertion | Select MAX704CSA only if design requires reset at 4.40V; otherwise MAX703CSA provides wider noise margin for standard +5V ±5% rails |
| MAX705CPA | 8-pin PDIP package, no battery backup, 4.65V reset, includes CE write-protect and watchdog timer | Used where board space permits DIP, no RAM backup needed, and watchdog supervision is required | Choose MAX705CPA only when watchdog timeout and write protection are mandatory and battery switchover is unnecessary |
Compared with MAX704CSA, the MAX703CSA offers higher reset threshold for improved noise immunity on nominal +5V supplies; compared with MAX705CPA, it trades watchdog/CE features for essential battery-backup capability in space-constrained SO designs.
Availability
MAX703CSA is available at Aetrix Electronics and suitable for industrial PLC controllers, medical instrumentation, embedded data loggers, and point-of-sale terminals requiring stable component supply across extended production lifecycles.
Supply support for MAX703CSA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.
The MAX703/MAX704 product line was designed specifically for cost-sensitive microprocessor systems needing integrated power monitoring, battery backup, and reset generation - eliminating discrete solutions in compact SO packages.
FAQ
What is the guaranteed reset threshold voltage for MAX703CSA?
The MAX703CSA has a guaranteed reset threshold of 4.65V ±150mV over temperature and supply variation. This means RESET remains asserted as long as VCC stays below 4.50V (min) and releases only after VCC rises above 4.75V (max), providing robust noise margin for +5V systems. The MAX703CSA datasheet specifies this parameter under Electrical Characteristics with test conditions VCC = +4.75V to +5.5V and TA = 0°C to +70°C.
Does MAX703CSA support battery backup for CMOS RAM?
Yes, the MAX703CSA provides automatic battery-backup switching for CMOS RAM via its VOUT pin. When VCC drops below 4.65V, the internal circuitry connects VBATT to VOUT through an 80Ω p-channel MOSFET, maintaining power to RAM. The MAX703CSA draws only 50nA in this mode, enabling multi-year operation from a standard 3V lithium coin cell. This function is fully detailed in the Backup-Battery Switchover section of the MAX703CSA datasheet.
Can MAX703CSA generate a reset pulse from a manual pushbutton?
Yes, the MAX703CSA includes a TTL/CMOS-compatible manual reset input (MR) that triggers a full 200ms reset pulse when pulled below 0.8V. The MR pin has an internal 250µA pullup, so a simple ground-switch connection suffices. This eliminates external debounce components, and the MAX703CSA's internal timer ensures consistent pulse width regardless of button press duration - a key reliability feature confirmed in the MAX703CSA Timing Diagram (Figure 2).
What is the maximum allowable backup battery voltage for MAX703CSA?
The MAX703CSA supports a maximum backup battery voltage of 4.80V, as specified in Table 2 of the official datasheet. Exceeding this voltage risks forward-biasing internal substrate diodes (D1 in Figure 3), causing unwanted current flow from VBATT to VCC when supplies are near the reset threshold. For lithium batteries, use 3.0V–3.6V cells; for supercaps, limit VBATT to VCC(min) + 0.6V (e.g., ≤5.35V for ±5% +5V supply), per MAX703CSA Applications Information.
How does MAX703CSA handle power-fail detection?
The MAX703CSA uses a dedicated 1.25V precision reference to compare the voltage at the PFI pin. When PFI falls below 1.25V, the open-drain PFO output goes low, signaling impending power failure. This allows early warning for µP-controlled shutdown. The MAX703CSA disables the PFI comparator in battery-backup mode (PFO forced low), and PFI input current is limited to ±25nA - enabling high-impedance monitoring of unregulated rails without loading. These behaviors are verified in the MAX703CSA Electrical Characteristics table.
MAX703CSA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.65V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX703CSA FAQ
1.How can I place an order for MAX703CSA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX703CSA on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX703CSA reliable?
The price and inventory of MAX703CSA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX703CSA is usually 5 days.
3.What payment methods are accepted for MAX703CSA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX703CSA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX703CSA?
MAX703CSA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX703CSA order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX703CSA?
For technical support, including MAX703CSA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX703CSA requirements.
6.How does Aetrix verify that MAX703CSA is sourced from the original manufacturer or authorized distributors?
All MAX703CSA products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX703CSA meets industry standards.
7.What is the process for return or replacement of MAX703CSA?
All MAX703CSA units undergo pre-shipment inspection (PSI). If there is an issue with MAX703CSA, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX703CSA part is unused and in its original packaging.
Return procedure for MAX703CSA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX703CSA Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
